Selected Targets from General Investigator programs

G011025 Targets

Decades of observations from the Mount Wilson and Lowell surveys identified magnetic activity cycles in many of the brightest stars in the sky. These unique data help to place the solar cycle in context, but the fundamental properties of the stars have large uncertainties. To better characterize the evolution of stellar cycles, we propose to determine asteroseismic masses and ages for a sample of stars with long magnetic activity time-series. Rotation is thought to be a key ingredient in stellar dynamos. With TESS we can also obtain independent constraints on the stellar rotation periods. These measurements will allow us to test the recent hypothesis that magnetic dynamos are disrupted in middle-aged stars, and that stellar cycles grow longer as stars age and rotate slower.

G011047 Targets

We propose to investigate the evolution of helium in the local solar neighborhood, in particular the (Delta Y/Delta Z) relation, using asteroseismic data of stars in the TESS Continuous Viewing Zone (CVZ). The helium abundance is one of the most poorly constrained inputs needed to construct stellar models, but it strongly affects a star's structure and subsequent evolution. Helium cannot be detected in the photosphere of most stars. Asteroseismology allows us to determine the helium abundance in the outer convection-zone of stars indirectly by modelling stellar oscillation frequencies, and directly by looking at the acoustic glitch signal of helium ionization. Stars in the TESS CVZ will allow us to study the (Delta Y/Delta Z) relation. Our target list has 188 stars in the southern CVZ.

G011048 Targets

Asteroseismology is a powerful method to determine surface gravities, masses, radii and ages of solar-type stars, and has become the "gold-standard" for calibrating more indirect methods. Here we propose TESS 2-minute cadence observations that will quadruple the current sample of solar-type stars with asteroseismic data, providing fundamental parameters for thousands of stars across the southern hemisphere. The sample will allow us to (i) determine the accuracy of asteroseismic scaling relations, (ii) precisely characterize exoplanets through their host stars and (iii) investigate mode excitation for hot solar-type stars. Our benchmark sample will also enable a wide range of ancillary science including fundamental calibrations of stellar granulation, spectroscopy, and gyrochronology.

G011060 Targets

The chemically peculiar (CP) stars of the upper main sequence (B0 to F4) allow the testing of current theories on stellar formation and evolution in the presence of a magnetic field, elemental diffusion and meridional circulation. Several subgroups exhibit an inhomogene-ous surface distribution of elements, which leads to spectroscopic and photometric varia-tions with the rotation period. Therefore, the rotation period can be directly measured which is unique among stars of these spectral types. The resulting sample of rotational periods will allow for an analysis of its behaviour among upper-MS stars, which we will correlate with stellar parameters derived from GAIA data. TESS data will also enable us to search for the effects of binarity in the light curves.

G011068 Targets

Stellar activity causes the sizes of cool stars to be larger than predicted by current stellar evolution models. However, stellar radii in eclipsing binaries are difficult to measure accurately from the ground because light curve distortions caused by star spots tend to change with time, and are seldom sampled well enough to model properly over a single orbital cycle. Folding the time series over many cycles introduces smearing, which biases the measured radii. This is a proposal to obtain TESS 2-min light curves of four active cool eclipsing binaries to address this problem, providing accurate radius measurements to advance our understanding of "radius inflation". The project will impact areas of astrophysics that use models to infer stellar properties, including exoplanet science.

G011073 Targets

Through the chemical enrichment of their environment, massive stars of spectral type O and B play an important role in many fields of modern astrophysics. Unfortunately, due to the limitations of ground based observational campaigns as well as previous and current space missions, tight observational constraints on their internal structure and evolution have so far only been possible for a handful of massive stars. With this science case, we aim to remedy this situation by studying 348 OB stars observed by TESS in the southern CVZ, and exploiting the synergies between binarity, asteroseismology and spectroscopy. A particular focus is placed on stars of spectral type B4 and earlier, of which none suitable for asteroseismic modelling were observed by the Kepler mission.

G011083 Targets

We intend to obtain very high precision light curves of a sample of detached eclipsing and spectroscopic binaries, which we have been monitoring spectroscopically for the last few years within the Comprehensive Research with Echelles on the Most interesting Eclipsing binaries (CREME) project. The light curves will be combined with our precise radial velocity (RV) measurements in order to obtain accurate and precise, absolute stellar parameters.

G011092 Targets

We have been monitoring a number of pulsating variables in the instability strip using specially designed filters. For a couple of these objects we have seen a drop in temperature that accompanied a phase jump in the data. These stars are often thought to go through a constant period change, which is attributed to evolutionary effects. However, we have examined one Cepheid and one delta Scuti which show a phase jump. A sequence of phase jumps could mimic a period change. However, at this point we have two known object which show the phase jump. The TESS observing program provides and ideal data set to examine a much larger data set with extensive coverage. We believe we will find a larger sample of phase jumping stars and be able to establish a rate at which they appear.

G011098 Targets

We propose to use the 30-minute-integration light curves of the 100 brightest blazars observable with TESS in Cycle 1 to see if the two classes of blazars (Flat Spectrum Radio Quasars and BL Lac Objects) emit variable optical light via the same or different physical processes in their relativistic jets. For five blazars near the south ecliptic pole, we will measure the incidence of flares and the fraction of time spent in high and low states for a full year. Our targets are gamma-ray blazars or candidate gamma-ray blazars pointed within 5 degrees to our line of sight; their emission is almost purely from the jets. The TESS time resolution will separate out individual flares and track fractal-variable emission on timescales accessible for the first time for a large number of blazars.

G011100 Targets

In this proposal we describe a novel technique for finding black holes (BHs) and neutron stars (NSs) in binary systems with MS stars. Specifically, we propose to look for the periodic magnification of the MS star caused by gravitational lensing by the BH or NS companion, which leads to an increase in flux on the order of 100--1000 ppm, lasting a few hours. Thus TESS is the ideal instrument for this search technique. We estimate that TESS will be able to detect and measure the masses of ~20 BHs and ~50 NSs with better than ~10% accuracy. Mass lower limits will be measured for over 200 systems, increasing the known population of galactic black holes by an order of magnitude.

G011103 Targets

We propose to produce, and make public, light curves for all ~100,000 known star cluster members brighter than T = 16 observed in the TESS full-frame images during Cycle 1. The light curves will be generated using an image subtraction photometry procedure which is essential for very crowded regions, and which we have applied successfully to observations obtained with very similar instruments to TESS. We will search the light curves for transiting planets, expecting to triple the number of transiting planets known in clusters, which will shed light on the timescales for processes in planet formation, evolution, and migration. The public data set will also be a gold mine for stellar astrophysics, including studies of gyrochronology, variability and tests of stellar evolution.

G011108 Targets

Warm Jupiters (WJs), giant planets with 10--100 day orbital periods, pose a major challenge to our understanding of how planets form and evolve. We need a larger sample of transiting WJs to test theories for their origins. However, the TESS core program will only discover a handful due to long orbital periods and low occurrence rates. Also, future SC and ground-based observations can yield valuable constraints on WJ properties, but prioritization based on observability and scientific value is needed to choose the best targets. We propose to discover and catalog WJs in full frame images; fit light curves of WJs discovered by our program and others; and produce a prioritized list of continuous viewing zone WJs as future SC targets and a prioritized catalog of WJs for ground-based follow-up.

G011112 Targets

TESS will follow in the footsteps of Kepler to become the world's pre-eminent mission for finding new planetary systems. Its high-quality photometry will also enable detailed studies of currently known transiting systems. We propose to obtain light curves of all 149 suitable systems in order to: (1) measure precise masses, radii and densities; (2) study orbital obliquity from starspot crossing events; (3) search for orbital decay, additional non-transiting planets, and moons from transit timing and transit duration variations; (4) identify rings around giant planets; (5) search for intrinsic variability in the planet host stars. These observations will form a dataset of unique quality and long-term legacy value; four of the five science goals can only be done using short cadence data.

G011113 Targets

We propose observations with 2-min cadence of 815 known and high-probability white dwarfs in Cycle 1 of the TESS mission. Our primary objective is to search these white dwarfs for transits of remnant planetary systems; transits of Earth-sized white dwarfs are likely to be very deep but also very short, just a few minutes, requiring high-speed observations. Our proposed photometry will also enable asteroseismology of dozens of known and high-likelihood pulsating white dwarfs, continuing the space-based revolution into the interiors of stellar remnants. From both asteroseismology and spot modulation of magnetic white dwarfs we will significant expand the number of white dwarfs with measured rotation rates, putting strong constraints on the endpoints of angular momentum in stars.

G011114 Targets

The interior structure of massive stars and the physical processes occurring within them are still poorly understood. Examples are interior rotation and angular momentum transport, internal mixing processes, mass loss through stellar winds, inconsistent opacities, the presence of large numbers of binary products, chemical surface peculiarity, and star formation histories in stellar aggregates. This proposal aims at addressing, and solving at least several of these problems by making large numbers of massive stars accessible to asteroseismic investigation. The present dearth of the required highly accurate space photometry of these stars will finally be removed by TESS' all-sky survey. To this end, 359 Beta Cephei-type pulsating stars are proposed as 2-min cadence asteroseismology targets.

G011122 Targets

We propose a method to break down the degeneracy in the mass-radius diagram by measuring the polar flattening of giant exoplanets. The first goal of our investigation is to measure the tide- and rotational-induced polar flattening of giant exoplanets from transit light curves. The second goal is to link this polar flattening to the fluid Love-number k2,f. Oblate-induced disruptions are more pronounced at the ingress/egress phases of short-period planet transits. The duration of these phases for a typical hot-Jupiter lasts for 10 to 20 minutes. Hence, TESS 2-minute cadence measurements are mandatory to reach the required time resolution that allows us to precisely observe these phenomena. Our project provides a third parameter for understanding internal structures of giant exoplanets.

G011123 Targets

We propose to observe all bright eclipsing cataclysmic variables (CVs) available to TESS during Cycle 1 (with a companion set to be proposed for Cycle 2) using the 2-min cadence mode for all. The 22 CVs cover a broad range of CV sub-type including nova-likes, dwarf novae, old novae, and magnetic CVs. The time resolution provided by the 2-min fixed cadence of the observations leads to high spatial resolution in the accretion structures. We will use the resulting data set to study the eclipses to provide insight to the accretion behavior. The eclipses will provide stringent tests of accretion models. Eclipse mapping will provide extended views of accretion behavior with time, revealing the on-going `life' of disks and other accretion structures.

G011127 Targets

The roAp stars are rapidly oscillating A-type stars that have strong magnetic fields and extremely high abundances in the rare earth metals. To date, only 61 roAp stars have been discovered. With TESS, we will observe all the known roAp stars in the Southern Hemisphere and find new ones. The significant increase in sample size and the improvement of noise characteristics in the pulsation frequency range will allow our team to: investigate the instability strip and consequently establish the pulsation driving mechanisms; probe the full range of pulsation periods; and determine the occurrence of non-pulsating Ap stars in the roAp star instability region. All the aforementioned results will be used to inform our theoretical models. For roAp star science, TESS offers a whole new ball game.

G011128 Targets

We propose to observe the active weak-line T-Tauri star CVSO 30 with TESS at 2 min cadence to test the hypothesis of an extremely hot and young transiting hot Jupiter. Ground-based photometry of the 2.7 Myr old star CVSO 30 revealed transit-like dips in flux with a short period of only 0.45 d. While strongly reminiscent of planetary transits, the observed flux dips change in shape and occasionally even appear to vanish. This challenges an interpretation in terms of a planet. Existing ground-based light curves mostly focus on the transit ephemeris and suffer from the usual limitations. A thorough study of the transits and variability in a system with a young and extremely active star like CVSO 30 requires continuous observations, which can only be provided by space-based instrumentation

G011129 Targets

We propose to observe 390 nearby stars that are not on the TESS core science target list --- 94% of these stars are within 25pc and the remaining 6% are the nearest cool subdwarfs within 60pc that will be used as key comparison test objects of minimal variability. A set of 254 nearby K and M stars will be observed in short cadence mode to (1) search for transiting planets, (2) study stellar short-term variability, (3) measure rotation periods, and (4) identify possible eclipsing binaries. Data from the full frame images for the remaining G stars will be evaluated primarily for science goals (2) and (3). Data for all 390 stars targeted via this proposal will be merged with other stars within 25pc in the TESS core science list to provide a homogenous dataset for all nearby stars.

G011130 Targets

AI Phe is the only subgiant star in an eclipsing binary system that is currently known for which asteroseismology is feasible with TESS. The mass and radius of the subgiant are known to better than 1% from the analysis of the eclipses and radial velocity data, and the luminosity has been directly measured via the parallax. Solar-type pulsations of this subgiant will occur with periods of about 24 minutes, i.e. unless 2-minute cadence data are obtained for this target, we will miss out on the best opportunity we have to critically test asteroseismology using TESS observations of a subgiant star.

G011132 Targets

Hierarchical multi-planet systems probe the formation and co-evolution of giant planets and their smaller companions. Only a dozen transiting hierarchical multi-planet systems (systems with giant planets and Super Earths) have been discovered so far. We propose to survey for hierarchical multi-planet systems with TESS. This project is expected to yield hundreds of transiting hierarchical multi-planet systems in the Full Frame Images, dozens of transiting companions in known giant planet systems, and a few tens of non-transiting companions in new planetary systems around TESS core science targets. Many of the systems from this survey will be around bright stars, for which we will conduct spectroscopic follow up studies on their eccentricity, obliquity and atmospheric properties.

G011133 Targets

With space asteroseismology we can measure the internal rotation of evolved stars. Subgiant stars are especially valuable because we can also measure their surface rotation, which is difficult or impossible for more evolved stars. Prior studies have given us strong evidence for cores rotating faster than their surfaces, but only for small subgiant samples. We request observations of 50 high-priority subgiant stars in the southern continuous viewing zone. A one year time series will yield high quality data capable of measuring internal rotation, and we have arranged complementary ground-based data to fully characterize these important targets. This powerful sample will permit tests of gyrochronlogy and stellar angular momentum evolution theory, and it has other broad applications.

G011144 Targets

We propose observing 35 RGB target stars in the TESS Cycle 1 field using both 2-minute data and full-frame images to search for exoplanets. Several surveys have targeted giant stars such as bright G and L giants and open cluster giants. We propose examining M8 RGB stars to investigate a poorly studied population of Neptune Jupiter mass planets around evolved stars. RGB stars span a wide range of stellar masses, luminosities, and chemical compositions thereby allowing studies of exoplanets in a variety of host star environments. RGB stars are also ideal targets to tackle two controversial and unsolved questions in exoplanet science: the occurrence rate of gas-giant planets as a function of stellar mass and the role of stellar incident flux on the radius inflation of gas-giant planets.

G011148 Targets

Debris disks serve as laboratories for studying planet formation and their presence is expected to correlate with that of planets. We propose 2-minute cadence photometric monitoring of a unique sample of 158 M and K dwarfs with debris disks to search for transiting planets and transiting disk material and collect a wealth of data on stellar variability and flares. Most of these targets are not in the CTL, and many are currently unpublished as disk hosts. The new data on stellar rotation and flares will help constrain stellar ages and test the hypothesis that flares can shape debris disks. Only one M dwarf debris disk/planet combination is currently known; our search could find another example of this phenomenon.

G011153 Targets

We propose to conduct the first systematic and statistically robust study of variability in very-low mass stars and brown dwarfs, enabled by the TESS mission's long-term continuous photometric monitoring, red sensitive passband and broad sky coverage. We will examine the light-curves of hundreds of spectroscopically verified ultracool dwarfs to characterize brightness modulations, measure rotation periods and determine flare rates, including a sample of 2 min cadence targets to study flare profiles and short duration variability. This study will fundamentally probe the nature of the atmospheric, structural, and rotational changes at the end of the stellar main sequence, and how these physical processes manifest as broadband variability through magnetic activity and weather.

G011154 Targets

Eclipsing binary (EB) science has long held renown for delivering accurate measurements of fundamental parameters: masses, radii, luminosities and temperatures. The field witnessed exponential growth in the Kepler era of ultra-high photometric precision, and the impact of TESS will be no less revolutionary. This multi-faceted proposal encapsulates three goals: (1) extract all known EB light curves from Full Frame Images (FFIs); (2) mine FFIs for as-of-yet unknown calibration-quality EBs, where simulations predict a 10-fold increase in the number of known EBs; and (3) acquire 2-min cadence observations for a prioritized list of targets that maximize scientific yield. The proposal discusses hot topics in the EB field and outlines the effort to provide these deliverables to the community.

G011155 Targets

The most powerful tests of stellar structure and evolution come from the brightest stars in the sky, for which complementary techniques can be combined. So far, naked-eye stars (V<6) have been rarely observed with high-precision photometry from space due to the large number of pixels required to capture saturated pixel columns. Here we propose adapt a low-pixel-cost technique, which our team pioneered for the K2 Mission, to produce high-precision 2-minute cadence light curves of all naked eye stars observable by TESS. The software tools and data products will enable numerous science applications, including tests of asteroseismic scaling relations for red giants, the detection of transiting planets orbiting naked-eye stars, pulsations in massive stars, and studies of interacting binaries.

G011158 Targets

We propose to use TESS 2-min cadence data to investigate 15 M-dwarfs of interest from the Next Generation Transit Survey (NGTS) that show short duration transits/eclipses. These include a confirmed planet (NGTS-1b), a m-dwarf/white dwarf system, and several MM eclipsing binaries. All targets show short timescale events that necessitate 2-minute cadence rather than the 30-minute cadence from the FFIs.

G011160 Targets

By covering a solid angle nearly 400 times larger than a single Kepler/K2 field, photometry from TESS Full Frame Images (FFIs) is expected to revolutionize time-domain astronomy over the coming years. However, light curves from FFIs will not be a standard TESS data product, and hence the success of science from FFIs relies on efforts by the community. Here we propose to develop and run a complete, end-to-end photometry pipeline for TESS FFI data, producing analysis-ready light curves for all FFI sources. Using powerful computing resources and software developed through community workshops within the TESS Asteroseismic Science Consortium, the light curves produced in this program will enable a vast array of science investigations across stellar astrophysics and exoplanet science.

G011163 Targets

Massive stars play an outsized role in the evolution of the universe through their roles in chemical enrichment and as Type II supernova progenitors. In this proposal, we plan to use TESS to perform asteroseismology on 26 B stars, primarily SPB and Beta Cep stars. All of our targets have previously been observed using high precision photometry from space with the WIRE satellite, and the combination of TESS+WIRE data of these stars will provide long timebase datasets inaccessible in any other way for this sample of stars. We will perform forward seismic modeling and compare results to our measured oscillation frequencies, constraining our models with known spectroscopic parameters. In addition, we will be able to observe stellar evolution occurring in real time with some of our targets.

G011164 Targets

Active binary stars are characterized by strong and variable chromospheric, transition region, and coronal radiation. Photometrically, the stars are variable primarily due to the presence of starspots, which trace the surface magnetic flux, and can yield insights into rotation rates, differential rotation, and activity cycles, along with activity levels, flux emergence, and spot morphology. We will examine 51 BY Dra, RS CVn, and FK Com systems, focusing primarily on starspots and flaring. With such a large TESS sample, we will be able to address the dependence of spot and flare behavior on broader stellar parameters and gain unique insight into the nature of rotation and activity among the most active cool stars.

G011170 Targets

Current constraints on stellar rotation around the zero-age main sequence (ZAMS) cannot constrain models for angular momentum evolution. As stars contract on the pre-main sequence, they spin up; once they reach the ZAMS, they begin to spin down due to braking by magnetized winds. Only a handful of rotation periods have been measured for Solar-type stars between 20-100 Myr so far. We propose to fill this gap by measuring rotation periods from TESS full frame images for ~60 Solar-mass stars in six 30-50 Myr-old open clusters. With these data in hand, we will place strong constraints on rotational evolution around the ZAMS, discriminate between models for different core-envelope coupling timescales, and investigate the dependence of activity on rotation in young Solar-type stars.

G011175 Targets

Planets and their host stars evolve with time, and the first few hundred million years are the most formative. By identifying planets at these ages, we can directly measure how exoplanets change over their lifetimes. K2 has significantly expanded this field by observing stars in nearby young clusters and star forming regions. However the sample of known young planets still remains small, and most orbit faint stars, hindering detailed follow-up. Here we propose to search for exoplanets around stars in nearby young moving groups, using both short-cadence and full-frame images from TESS. With this, we will dramatically expand the number of known infant (<200 Myr) planets, including those orbiting stars bright enough for detailed mass measurements and atmospheric characterization.

G011176 Targets

We propose two-minute TESS observations of a sample of 481 directly imaged young and intermediate age stars in order to characterize the distribution of material on their innermost orbits. We will search for the closest ``dipper'' events---belived to be the result of magnetospheric accretion or disk warping due to a companion---and, with a set of well characterized stellar properties, measure the occurence rate of the dipper phenomenon with stellar properties and circumstellar environment. We will also search the dozen disks with known edge-on inclinations for disk-transit events. We will derive rotation periods for all sources with rotation-modulated lightcurves to improve their age estimates, which are vital to understanding the completeness of direct imaging exoplanet surveys.

G011177 Targets

Kepler data revolutionized asteroseismology, allowing us to develop the necessary tools. But it did not observe enough pulsating subdwarf B (sdBV: extended horizontal branch) stars to constrain some key bulk properties, like total and core masses. TESS can provide that. sdBV stars allow us to probe post-helium flash and helium-fusing cores. GAIA will provide distances and radii, TESS seismology will provide core masses and internal structure across differing evolutionary paths. Our proposal has 3 main objectives: 1) determine evolutionary core mass sequences of horizontal branch stars. 2) Determine angular momentum evolution across the helium flash and between interacting binaries; and 3) characterize radially differential rotation as a probe of core-envelope interactions.

G011178 Targets

We propose to use photometry and FFI from TESS data to identify stars that show flare activity, potentially to identify stars which exhibit superflares, and to correlate those data with known indications of magnetic activity such as calcium line variability, periodic flux variation, and spectropolarimetry that is a consequence of the rotation of the star with spots.

G011179 Targets

We propose TESS observations of a unique set of bright main-sequence and subdwarf stars for which we have age constraints from a wide, coeval white dwarf companion. The white dwarfs in the 62 currently known common-proper-motion systems visible in Cycle 1 span a range of total ages, from roughly 300 Myr all the way up to more than 10 Gyr. The majority of the main-sequence primaries are K and M dwarfs, for whom most age inference methods yield only imprecise estimates. Our observations will constrain age-rotation and age-activity relations at old ages. A major advance will occur in 2018 April, when Gaia DR2 will enable the discovery of hundreds if not thousands of new suitable binaries, which we will explore using the 30-min full-frame images.

G011180 Targets

We propose to use TESS data to investigate planetary systems orbiting cool dwarfs spanning a range of masses, metallicities, and ages. TESS will survey 13 times more cool dwarfs than Kepler and K2 combined, thereby enabling sophisticated analyses of how the prevalence and properties of planets depend on host star characteristics. Using our planet detection pipeline, we expect to detect roughly 90 Earth-sized planets, 360 Super-Earths, and 1460 Sub-Neptunes in the Full-Frame Images of nearly 1 million cool dwarfs. Many of these worlds will be individually interesting as targets for future mass measurement or atmospheric characterization, and planet occurrence calculations using the full planet sample will reveal new insights into the formation and evolution of planetary systems.

G011183 Targets

The field of exoplanets has progressed beyond planet detection to characterization of planetary systems. This includes planetary structure and atmospheres, system architectures, orbital dynamics, and the studies of exoplanet host star properties. The characterization of known exoplanets is therefore a critical component of the on-going expansion of the field. This proposal aims to ensure that all known southern hemisphere exoplanet host stars are included in the TESS target list. The three main science goals of the observations are: (a) observations of potential transits and phase variations, (b) refined transit ephemerides enabling spectroscopic follow-up with future space-based facilities, and (c) detailed stellar properties through astroseismology modeling.

G011184 Targets

Gaseous giants orbiting stars more massive than the Sun are found regularly in RV surveys targeting giant stars. These planets show significant differences in their properties with respect to those around dwarfs. The origin of the differences can be searched in i) planet formation processes, ii) effect of stellar evolution, or iii) observational biases. We have been following 640 giants stars from the field for 10 years with good RV precision with the Coralie spectrograph. We detected 50 to 70 planets to be published. TESS observations with 2-min cadence for these stars will be very important: 1) For a search of potential transits of the planets; 2) asterosismology estimate of the star masses & radii; 3) to quantify and characterise the star variability (modelling or CHEOPS observations).

G011185 Targets

To understand the link between stellar "superflares" observed in Kepler, and solar flares, we must establish an observational link between the physical processes occurring in each. Quasi-periodic pulsations (QPPs) with periods up to tens of minutes are a common feature of solar flares that appear exist in stellar flares, and are ideal for detection in high cadence photometry from TESS. We propose to carry out a survey for QPPs in stellar flares and superflares using TESS. These QPPs will be analyzed using a range of new statistical techniques, including analytic modeling, Gaussian Processes, and Empirical Mode Decomposition. This will produce the most robust catalog of stellar QPP properties, as part of our team's ongoing study in connecting solar and stellar flares.

G011187 Targets

We propose for TESS observations of two "redback" millisecond pulsar systems, 3FGL J0523.3-2528 & PSR J1023+0038. No radio or gamma ray pulses have yet been detected from the neutron star in J0523. Two min cadence optical data of J0523 will enable us to refine the orbital parameters of the system and thus allow us to perform a targeted search for the pulsar's period in Fermi data. J1023 is one of three transitional systems and is currently in a low mass X-ray binary state. Optical light curves have revealed a puzzling behaviour in which the flux varies between two well defined modes. TESS observations will allow us to study the mode switching in J1023, in particular the fraction of time spent in each mode, which will help us to understand the accretion flow close to the neutron star.

G011188 Targets

We propose an ambitious campaign for extracting granulation parameters and asteroseismic parameters for large samples of evolved stars in the TESS fields. Even with the minimum 27 day baseline we estimate that up to 2.3 million targets could have at least some measurable asteroseismic parameters, covering a substantial fraction of the Galaxy and permitting unprecedented galactic archeology studies. We justify our predicted yields and present a comprehensive analysis and follow-up plan to take advantage of the unique capabilities of TESS as a stellar population discovery engine.

G011190 Targets

The occurrence rates of planets orbiting early-type stars are important for our understanding of planet formation and subsequent evolution. We propose to use TESS to observe all known lambda Bootis stars to test the hypothesis that their peculiar chemical abundance patterns are a direct consequence of the presence of giant planetary companions. Lambda Bootis stars are A-type stars that were found to exhibit an under-abundance of Fe-peak elements while their abundances of lighter elements are normal. One possible scenario to explain these abundance patterns is that young lambda Bootis stars selectively accrete material from the circumstellar disk which is dynamically separated by the presence of a massive planetary companion. Our proposed study will test this hypothesis.

G011197 Targets

We propose to obtain TESS light curves for every accessible member of the Hyades, the benchmark 625-Myr-old open cluster. We expect to measure new rotation periods for >200 Hyads, primarily for stars ignored by previous rotation surveys. Because the Hyades is one of the nearest and best-studied open clusters, empirical calibrations of the age-rotation-activity relation (ARAR) often interpolate between the observed properties of Hyads and those of the Sun. Our TESS data will therefore be critical to improving the anchoring of the ARAR, and will build on our experience with surveys for rotation. Furthermore, combining TESS data with archival and new optical and UV spectroscopy and X-ray observations, we will provide new constraints on the operation of stellar dynamos and on magnetic braking.

G011198 Targets

One of the most profound results to come out of Kepler is that the most common type of planet in the Galaxy, within ~100 day periods, are "super-Earth" exoplanets. Because they are so common and because we lack a (known) planet of this size in our solar system, understanding the formation mechanisms and compositions of super-Earths is of great interest. However, as of now only a small fraction of super Earth planets have mass measurements. We propose TESS observations to search for planets around ~100 dwarf stars, not prioritized by the TESS science team, for which we have in hand existing radial velocity observations from Magellan/PFS. We will immediately place mass constraints on any detected planets, and expect to significantly increase the super-Earths with composition constraints.

G011200 Targets

Rotation is a powerful and under-utilized stellar diagnostic: it carries information about the ages, masses, magnetism, and interaction histories of stars. We propose to utilize TESS Full-Frame Image data to measure surface rotation rates and photometric magnetic activity proxies in dwarf and subgiant stars in the Southern Continuous Viewing Zone and Asteroseismic Target List. This sample will enable important tests of unexpected behavior in the Kepler rotators, allow us to refine physical models of angular momentum evolution, provide anchors for period-age and activity-age relations, and ensure that the potential of rotation periods for stellar characterization is fully realized for broader science with TESS.

G011203 Targets

The evolution of planetary systems after the main sequence is largely unknown and no planets around isolated White Dwarfs (WD) have yet been detected. Some show evidence of metal pollution or gas and dust discs indicating that planetesimals and even dwarf planets up to the size of Pluto strayed too close to the WD and have subsequently been tidally disrupted. However there is only one known system where this can be actively observed, WD1145+017. Such objects would only survive a star's evolution to a WD at distances greater than at least 1AU, implying these objects may have been scattered by unseen planets. We propose to observe all WDs with magnitudes <16 with similar evidence of planetary systems to search for further examples of ongoing tidal disruption of planetesimals.

G011204 Targets

Space-based photometry provides an unprecedented view into stellar variability, revealing detailed information about pulsation, rotation, circumstellar variability, and other changes taking place in the star or its environment. However, recent efforts have largely neglected the high-mass end of the main sequence, mostly due to relatively small fields of view. The full-sky coverage of TESS can remedy this, as massive stars are spread over a large area. We propose to observe massive, rapidly rotating pulsators that eject mass and form disks, including the Be and Bn subtypes. These systems are valuable astrophysical laboratories for both stellar and disk physics, and the connection between them.

G011208 Targets

Stellar ages typically have large errors (~4 Gyr), but with Kepler it was possible to estimate ages with better precision through asteroseismology, yet their precision depends on how precisely we know the temperature and metallicity of stars. Different burning problems in stellar physics, such as the apparent rapid rotation and flat magnetic activity of old stars, depend critically on precise ages. We take advantage of a sample of solar twins with precise stellar parameters, to estimate precise seismic ages with TESS, to assess if gyrochronology is still valid in stars around solar age, verify the decrease of stellar activity with age and calibrate the decay of stellar lithium with age. Finally, our improved age calibrations will contribute to constrain ages of planets discovered by TESS.

G011209 Targets

In 2018, HST's Cosmic Origins Spectrograph (COS) will carry out a far-UV survey ("EclipSS") of 49 carefully-chosen nearby solar-type (F2-K2) dwarfs, located near the ecliptic poles. These areas are favored by two important up-coming missions: TESS (photometry/exoplanets) and eROSITA (X-ray all-sky survey). The targets were chosen to be isolated (good for TESS and eROSITA), bright enough for TESS and eROSITA, but not too bright for super-sensitive COS. FUV emissions and X-rays are tracers of stellar activity, for which TESS can provide supporting rotation periods, flare frequencies, and seismology. The multiplexed sample will provide an unprecedented view of the magnetic engine - the Dynamo - at the heart of activity, which among other things can affect exoplanets and their habitability.

G011211 Targets

We propose for TESS 2-minute cadence observations of 73 single-lined EBs with M dwarf secondaries to precisely measure the primary and secondary eclipses. We will jointly analyze these eclipses, radial velocities (RVs), Gaia parallaxes, and already available spectral energy distributions (SEDs) to explore the effect of binary interactions on the observed M dwarf radii and effective temperatures, which are known to disagree with models by 5-10%. We can further improve the precision on these parameters with granulation-driven surface gravities from the 2-minute cadence data and the addition of spectrophotometry from Gaia and the proposed SPHEREx mission.

G011214 Targets

We propose to extract and analyze TESS light curves for all 1666 candidate transiting planet systems in the Southern ecliptic sky that have been identified by the HAT ground-based transit surveys, and which are not among the top priority TESS targets. These light curves will be used to confirm and characterize transiting planets, including giant planets around M dwarfs, to look for additional transit signals in the light curves, to check for transit timing variations, and to calibrate the follow-up efficiency of the HAT surveys. We propose 2 minute cadence observations for 139 targets where high cadence is necessary, the remaining 1527 targets will be analyzed using the full-frame images.

G011215 Targets

We propose to develop a tool for creating "variability finder charts" from the TESS Full Frame Image (FFI) dataset. When observers plan a ground-based transit observation, we often need to pick appropriate comparison stars, which assume to be photometrically quiet. For the first time, thanks to the TESS FFIs, the data will be available over nearly the entire sky to assess the intrinsic variability of every star within our potential field of view. Our proposed tool for automatically generating finder charts that include information about variability will support the TESS Community Follow-Up Observing program, other exoplanet observing programs, and other bright-star time-domain investigations across all of astrophysics. This tool will be open-source, easy-to-install, and easy-to-use.

G011216 Targets

Exoplanets around nearby small stars present the best opportunity for future atmospheric studies with the James Webb Space Telescope and the ground based ELTs under construction. While TESS will be monitoring the bright nearby stars for transiting planets, two recent discoveries by MEarth (GJ 1132b and LHS 1140b) will also be visible in the southern ecliptic hemisphere survey. Both of these targets are currently in the JWST GTO programs. However, interpreting the spectra that JWST will soon return requires understanding the energy input at the top of their atmospheres. We propose to utilize TESS s unique capability for continuous monitoring to measure the flare rate and energies from GJ 1132 and LHS 1140 in order to better interpret future atmospheric data.

G011219 Targets

Utilization of our Solar System as the model planetary system long has implications for exoplanetary studies. Complementary to exoplanetary studies which have found a high proportion of giant planets to their host stars, evidence within our own Solar System has been found for migration of the giant planets during the Solar System's Terrible Twos. Dynamical models suggest that some Kuiper Belt Objects, comets and Jovian resonant asteroids originated in the same source reservoir but unfortunately studies of surface composition are inadequate to test this hypothesis. We therefore propose to use TESS FFI data to study the Jupiter resonant asteroid populations in an effort to determine where they originated.

G011221 Targets

We propose to determine accurate relationships to convert M dwarf absolute magnitudes and rotational periods to stellar masses and radii. We will achieve this by searching for, discovering and characterizing new low-mass stellar eclipsing binary stars in the TESS full-frame images. Our team has the tools and experience necessary to successfully execute the proposed research and achieve the proposed goals: The PI leads the TESS Cool Dwarf Team that produced the TESS Cool Dwarf Catalog. The Co-I, BU Ph.D. candidate E. Han, leads a robust in-house data reduction and ground-based follow-up program for Kepler eclipsing binary stars currently funded by a NASA XRP award. With funding from the TESS Cycle-1 program we will apply our existing Kepler pipeline to the TESS FFI data.

G011224 Targets

Hot stars represent a relatively unexplored population of planetary hosts. Bright and nearby hot stars represent ideal hosts for exoplanetary atmosphere characterization given their very different spectral qualities (e.g., a small number of broad, shallow lines) and their low levels of stellar activity. We propose observing a sample of 453 stars with spectral types A9 and hotter with magnitudes brighter than 7.5 Tmag and that reside within 100 parsecs of the Sun. These observations will be able to detect super-Earth planets, provide constraints on planet formation and system architecture for hot stars, and supply ideal, and likely cloud-free planets for atmospheric characterization.

G011225 Targets

Binary stars with precise masses have for long been valuable benchmarks to probe the input physics of stellar models, and for helium and age determination. This will be reinforced in the context of Gaia, TESS, and PLATO but, even with precise masses, uncertainties like those related to abundances, hamper this potential. To complement Gaia data, we are involved in SB spectroscopic and astrometric observation campaigns at OHP & VLTI (Halbwachs+2014, 2016, Kiefer+2016, 2017). For 10 SB2s, we derived masses with a precision better than 1% (G-K stars) and 3-4% (F stars). A seismic analysis of these systems with TESS will allow to estimate their initial helium abundance and age, and improve the modeling. Our target list includes three systems in the TESS-ATL with a seismic detectability >60%.

G011227 Targets

The occurrence rate of planets as a function of planetary mass and orbital period, and of stellar mass, provides powerful constraints upon models of planet formation, migration, and evolution. Kepler has provided such measurements for FGKM stars, but the short-period planetary population of more massive stars is largely unexplored. We propose to use TESS to observe a sample of A-type main sequence stars in order to find hot Neptunes around these stars. This will provide the first measurement of the occurrence rate of small planets around intermediate-mass stars, increasing our knowledge of planet formation and migration around these stars. It will also provide an excellent sample of planets for studying the impact of high-energy radiation upon planetary atmospheric escape.

G011229 Targets

About 20% of the TESS transit detections will be for planets with only a single transit in the TESS light curve. These systems are especially interesting, since they represent planets at longer orbital periods and therefore a much wider range of equilibrium temperatures. However, without an accurate periods for those planets, it is not possible to schedule future transit observations to measure atmospheric properties or other characteristics. We propose a project that will apply existing photometric data from the KELT transit survey to precover the ephemerides for a significant subset of the TESS single-transit events, including Neptunes out to 25-day periods and Jupiters out to 300-day periods. This effort can be applied to planets detected in both the 2-minute data and the FFIs.

G011230 Targets

The search for transiting planets in clusters has been unsuccessful from the ground, and slow from space due to the limited sky-coverage of current space telescopes. With TESS, an all-sky mission, the TESS Open Cluster Survey will more than double the current number of cluster planets in Year-1 alone. Importantly, each TOCS planet will have well known physical properties, including age, making it a benchmark system placing important empirical constraints on models of the formation, evolution, and long-term survival of planets, planetary systems, and planetary atmospheres. An expanded population of cluster planets will also provide much needed guidance to N-body modelers seeking to better understand the dynamical evolution of planetary systems in potentially hostile cluster environments.

G011231 Targets

M dwarfs account for 75% of all stars. The nearest M dwarfs are the most easily studied; moreover, for the coming decade, the only spectroscopically-accessible temperate, terrestrial worlds will be the ones that transit the closest mid-to-late M-dwarfs. Key stellar properties remain uncertain, notably their magnetic activity, rotation periods, and multiplicity. We propose to gather TESS 2-minute cadence observations of the volume-complete sample of mid-to-late M dwarfs within 15 pc. Short cadence is essential to determine the flare morphologies; we will also measure rotation periods, and precisely measure radii for new-found eclipsing binaries. We will combine the TESS light curves with our ongoing high-res spectroscopic survey to yield a legacy dataset of our closest stellar neighbors.

G011233 Targets

Our understanding of the evolution from circumstellar material to the thousands of planetary systems discovered to date, is limited. One means to constrain the size and composition of this planet-forming material is to observe a YSO being eclipsed by circumstellar material. These events are rare but have led to such insights as Saturn-like rings and gaps in the disk surrounding the a young planet. We propose to search the TESS data to discover and characterize new eclipses caused by occultations from circumstellar material. Additionally, we ask that both PDS 110 and J1407 be placed on the 2 minute cadence target list, as they are the only circumplanetary disk candidates known to date. This proposal will allow us to gain insight into the formation of Saturn-like ring systems and satellites.

G011235 Targets

We propose TESS monitoring of a selection of seven bright cataclysmic variables (CV) during Cycle 1. Our sample of magnetic accretors and eclipsing systems that show superoutbursts have special properties that demand continuous, fast-cadence observations. Our studies of CVs with K2 have demonstrated the importance of such data in constraining the physics of magnetic accretion onto white dwarfs and the development of instabilities in disks. Our targets have not been observed by K2, so TESS provides a unique opportunity to obtain continuous coverage at high cadence for these rare CV systems.

G011237 Targets

TESS full frame images (FFIs) are expected to contain more than 10,000 transiting planets and hundreds of thousands of eclipsing binaries; they will also be broadly useful throughout time-domain astronomy if light curves for targets are easily accessible for all. As the developers of the only FFI pipeline for the Kepler mission and the highest precision automated light curves for K2, we propose to produce and release to the community light curves for 25 million objects observed by TESS during Cycle 1, making the data public within one month of each data release. We will search these light curves for transiting planets and eclipsing binaries, releasing all of our software, data products, and catalogs to the community in order to maximize the science that can be quickly enabled by TESS.

G011238 Targets

Kepler K2 observations reveal that a significant fraction (>10%) of local M dwarfs with low reduced-proper-motion values are fast-rotators, with periods <4days. Most of them also show evidence of flaring activity in the long-cadence K2 light curves. High-cadence monitoring would however be idea to characterize the flaring behavior. Close examination of UV/optical/infrared colors reveals that these fast rotators occupy a distinct locus in color-color space. Based on these results, we have designed a selection algorithm that identifies young flaring M dwarfs with a high success rate (~28%). We propose to monitor 923 of these candidates in the high-cadence 2-minutes mode, to measure rotation rates and monitor the flaring behavior in a large sample of M dwarfs in unprecedented detail.

G011239 Targets

We live in a planetary system around an active star, so understanding where in our Galaxy other systems with life are located is one of 21st century astronomy s most urgent scientific questions. M stars offer a wealth of close-in planet detections including bodies in what is considered the liquid water habitable zone (HZ). Coupled with their proximity and the abundance of such systems, they are appealing targets for Earth-like exoplanet searches. However, the frequency of high-energy flares from M stars dictates where the HZ ends for surface life, and can be used to predict the spectra of planets that will be the topic of detailed investigation over the next decade. We seek TESS 2-minute data for 14 well-dated, young M0-M1 stars to map the early evolution of flaring activity.

G011241 Targets

Gyrochronology, an empirical relation between rotation and age, is believed to be among the best current methods of stellar age determination. We propose a robust test of that hypothesis using about 1280 wide binary data using TESS. This data also will support our study of flaring rates among the low-mass M-type dwarfs. Wide pairs offer a unique opportunity to unravel and to calibrate the rotation-activity- metallicity-age relations for main sequence stars because components of a binary should have rotation and activity levels consistent with their masses and common age. Our proposed investigation has two objectives: 1. Calibrate the stellar rotation age paradigm using wide main sequence binaries 2. Quantify the flaring rate among the MS+MS binaries as a function of age

G011242 Targets

As TESS searches for transiting exoplanets orbiting bright stars, any supplementary information that can indicate the existing presence of a transiting planet will boost the mission detection rate. The KELT transit survey has been searching for transiting planets around similarly bright stars for over a decade, and has an existing list of 150 transit candidates in the southern ecliptic sky that are observable by TESS. We propose these targets for 2-min TESS observations to help confirm the planets and precisely measure their transit parameters. We expect these candidates to yield between 5 and 10 new transiting giant planets around bright stars, which will be excellent targets for future transit observations and characterization.

G011247 Targets

We propose to solve two mysteries surrounding magnetic dynamo evolution using TESS Full Frame Images (FFIs). Firstly, we will establish whether a newly discovered bimodality in the distribution of rotation periods is produced by a local star formation history perturbation or a previously unknown feature in the magnetic dynamo evolution of young, cool dwarfs. This will be achieved by measuring rotation periods from TESS FFIs for stars at a range of galactic positions. Secondly, we will calibrate the gyrochronology relations at old ages using TESS-HERMES spectra and Gaia proper motions. We will also quantify the precision and accuracy of gyrochronology using Gaia comoving pairs. Finally, we will provide a catalog of ~ 1 million rotation periods for TESS FFI stars.

G011250 Targets

Solar flares and their accompanying coronal mass ejections pose a risk to our society due to ground-induced currents on the power grid. The 1859 Carrington event was the largest flare/CME to impact Earth in the past 158 years. Such an event today would have catastrophic consequences. The rate of solar superflares, and hence the risk, is only poorly known. Solar and stellar flares follow a power-law distribution in energy; TESS can detect white light flares on G stars a factor 3 brighter than the Carrington flare. We propose to examine the light curves of the G dwarfs imaged by TESS with a 2m cadence for white light flares. The result will be an improved estimate of the superflare rate on solar-like stars, and a better understanding of the risk the Sun holds in store for us.

G011257 Targets

Small planets on short-period orbits are the most common product of planet formation, and atmospheric measurements provide the only way to assess their detailed compositions. However, so few of these planets have been studied that we cannot reliably infer trends of atmospheric composition, aerosols, and/or chemistry versus UV or O/IR irradiation, planet mass, stellar type, etc. We need a larger sample. We propose a new set of TESS targets, derived by prioritizing stars most likely to host transiting planets whose atmospheres JWST can easily characterize. Our program program will increase the expected yield of such planets by 50\% compared to the CTL, finally providing a large enough sample of warm Neptunes to identify the trends (if any!) linking stellar, planetary, and system properties.

G011259 Targets

We request high-cadence observations of 59 nearby RR Lyrae for which Gaia will yield precise parallaxes and proper motions. The plan is to investigate how the luminosity scatter in the RR Lyrae period-luminosity relation is associated with higher-order moments in the shapes of their lightcurves. This campaign will be complementary with other concurrent campaigns such as Brava-RR, the Apogee RR Lyrae program, and the Carnegie RR Lyrae program. TESS is the only facility capable of providing lightcurves that are high-precision, densely-sampled, and of uniform systematics across the whole sky.

G011264 Targets

Flares have become a key observable signature of stellar magnetic activity in photometric surveys. The occurrence rates for these events have been found to correlate with other measures of magnetic activity, such as X-ray or UV emission, which decline as the star ages. Active stars can produce superflares, up to 1000x larger than those on the Sun, which may affect planet habitability. Further, frequent small flares can hinder transiting exoplanet detection. We propose to create a census of superflares for active GKM stars in the solar neighborhood using TESS. This program has the potential of discovering thousands of new flare stars across a range of spectral types, and will be key for characterizing the habitability of nearby exoplanets

G011265 Targets

Understanding the physical mechanisms driving the formation and early evolution of extrasolar planets is one of the most debated topics in modern astrophysics. Open clusters are the birthplace of most stars and are composed of coeval stellar populations with accurate age determinations. Therefore, they are the best laboratories to address these open issues. Here, we are proposing to collect 2-min cadence photometry for ~800 stars in young (1-80 Myr) clusters and associations to detect new close-in planets. The results of our study will allow us to: a) constrain current models on the early stages of planet evolution; b) discover the mechanism leading to planet migration; c) study the effect of the environment on planet formation.

G011266 Targets

M dwarfs (M < 0.7 MSun) are prime targets in the search for Earth-like worlds, yet their high levels of magnetic activity may make them unsuitable habitable planet hosts. Their magnetic activity is driven by rotation and convection, evolves over time, and is manifested in part as frequent, unpredictable, and energetic flares. Via high-energy radiation (X-ray/UV) and energetic particle emission, flares drive exoplanet atmosphere chemistry, erode atmospheres, and impact habitability. We propose a TESS M dwarf flare program that will provide crucial information on the cumulative energy output from M dwarf flares, place constraints on which M dwarf planets are most likely to be habitable, and inform target selection and analyses in exoplanet follow-up studies using JWST.

G011268 Targets

Accretion is responsible for the growth and evolution of most objects in the Universe, yet many unanswered questions remain in accretion disk physics. We propose to observe a sample of 59 accreting compact objects (comprising a mix of accreting white dwarfs, neutron stars, and stellar-mass black holes) at 2-minute cadence with TESS. These observations will provide the first probe into long-timescale accretion-induce variability for many object types, allowing for both studies on individual objects and ensemble analysis to compare accretion variability across different accretor types. We will also co-ordinate X-ray observations to be simultaneously performed on some targets, allowing us to study X-ray/optical time-lags on week timescales.

G011270 Targets

We propose the characterization of outbursts in southern Be stars. Classical Be stars are rapid rotators of spectral type B and luminosity class V-III which have an equatorially concentrated circumstellar disk. The disk is fed by discrete mass loss events called outbursts. Rapid rotation alone cannot explain the ejection episodes, and non-radial pulsations (NRP) have been proposed as an explanation. We propose to verify the correlation between the NRP regime and the feeding of the envelope by combining ground-based spectroscopy data with the identification of outbursts and the measurement of small changes in pulsation frequencies with TESS 2-min cadence observations. Fourier analysis of photometric data will be performed using a methodology developed by our group for CoRoT and K2 Be stars.

G011273 Targets

There are ~50 known planets around M dwarfs, but only one system around an ultra-cool (>M7) dwarf: Trappist-1. Ultra-cool dwarfs are arguably the most promising hosts for atmospheric and biosignature detection in transiting planets because of the enhanced feature contrast in transit and eclipse spectroscopy. We propose a pilot TESS survey to continuously monitor six of the brightest ultra-cool dwarfs over 27.4 days. To maximize the probability of detecting transiting planets, we have selected only targets seen close to equator-on. Spin-orbit alignment expectations dictate that the planetary systems around these ultra-cool dwarfs should also be oriented nearly edge-on. Any planet detections in our pilot survey will immediately become top priority targets for JWST transit spectroscopy.

G011278 Targets

M-dwarfs are enticing targets for exoplanet surveys because the planets in the habitable zones of these stars have comparatively short orbits and are much easier to detect and characterize than planets around more massive stars. However, how well we can know these planets is related to how well we know their host stars. There are few well-characterised M-dwarfs that can be used to establish an empirical relation. As such, investigation of planets orbiting M-dwarfs will be frustrated. The low mass eclipsing binary (EBLM) program has measured the masses and, characterised over 200 binaries composed of F/G+M stars in a consistent manner and so stands to improve the situation. However, require a consistent set of lightcurves to measure their radii and establish such a relation.

G011279 Targets

Historically, monitoring the evolution of a Cepheid's pulsations required a significant investment of telescope time. The advent of wide field photometric surveys, provides excellent datasets for carrying out period change studies on a large number of Cepheids. However, the observing cadence of most ground-based sky surveys and the day-night cycle prevent the study of short-term, especially cycle-to-cycle, Cepheid period variations and jitter. The original Kepler field contained just one Galactic Cepheid, and K2 has returned data on maybe a dozen more. But at last, TESS will allow us to carry out ultra-high precision, ~month-long (or longer) continuous photometry of the majority of known Galactic Cepheids. This will fundamentally alter our understanding of Cepheid variables.

G011280 Targets

Exoplanets undergo the most dramatic changes in their orbital, radius and atmospheric properties in the first few 100 Myr after formation. The most crucial sample for evaluating model of exoplanet evolution (such as migration) are the youngest planets (<50 Myr). We propose short cadence and FFI analysis of all members of the 10-20 Myr old Sco-Cen association, the home of the vast majority of young stars in the nearest 200 pc volume. We will implement PSF fitting for FFI data, apply our young star specific transit-search pipeline to both SC and LC data to identify transiting planets for follow-up, and perform injection-recovery tests to measure occurrence rates at very young ages. In total, we propose to observe 1722 targets with T<13 for 2min cadence.

G011281 Targets

What happens to the planetary systems after the red giant (RG) expansion is largely unknown. Theory predicts a gap in the distribution of orbital periods, due to the opposite effects of stellar mass loss (planets pushed outwards) and tidal interactions (planets pushed inwards). Hot subdwarfs (HSDs) are peculiar stars that lost almost all their envelope near the tip of the RGB. The envelope ejection may be related to common envelope (CE) evolution and indeed ~50% of these stars are in post-CE close binaries. The other half HSDs may have experienced the same CE ejection by a fainter companion (massive planet or BD), that may or may not have survived the RG phase. In order to heavily test this hypothesis we propose to observe 932 apparently single HSDs with Tmag<=16 searching for transits.

G011284 Targets

Our X-ray surveys of a small sample of cool AGB stars with FUV excesses reveal X-ray emission in 40% of our sample. The X-ray emission shows the unexpected presence of magnetically-confined and very hot gas (Tx~35-150 MK), and quasi-periodic variations on hour-long timescales, likely associated with an accretion disk around a main-sequence companion. Recent HST UV observations show flickering on ~minute time-scales for our key fuvAGB object, confirming the presence of an accretion disk. We propose a TESS survey to search for such fast variations in TESS's optical band for a statistical sample of AGB stars with UV emission. The resulting database of high-cadence, high-sensitivity light curves will provide an unprecedented window into binary interactions in AGB stars.

G011285 Targets

We propose to generate high-precision light curves for a sample of ~500 young (1-5 Myr) intermediate mass stars using TESS full frame images at 30-minute cadence. Ground-based observations inform us that young BAF stars are variable due to a combination of accretion (for the Herbig AeBe objects), circumstellar obscuration, and starspots. However, detailed studies of this variability and its relationship to the stellar environment have never been carried out on a large scale. With TESS, we will perform the first comprehensive analysis of light curve morphology among young, intermediate-mass stars and its relationship to magnetic activity as well as circumstellar disk properties. The results will be compared to our previous space-based work on low mass K/M stars in young clusters.

G011286 Targets

We propose a photometric survey of magnetic massive stars using TESS to detect and characterize three types of variability of these objects: rotational modulation, stochastic variations and pulsations. This will lead to precise rotational period determinations and will help probe magnetospheric structure, as well as dynamic flows within. Detecting pulsations will provide a means to link surface magnetism to the internal structure and better understand surface spindown due to magnetic braking, yielding critical information for stellar evolution models. Given its high precision, rapid cadence and long temporal baseline, TESS provides us with a unique opportunity to detect all three forms of variability, which will prove critical in testing and improving our knowledge of these stars.

G011288 Targets

Most stars harbor exoplanets and end their lives as white dwarfs, yet we do not yet know if white dwarfs themselves host planets. Metal contaminated white dwarfs, evidence for disintegrating planetesimals and planets around pulsars all imply that planets may indeed be common around such stars. TESS will observe the SDSS fields where most white dwarfs have been detected, and thus is well-placed to conduct a survey for transiting planets. Simulating realistic light curves, we anticipate that TESS could discover several white dwarf planets in the Southern sky during its first year of operations. We propose to observe 3945 white dwarfs brighter than 18th magnitude and analyze the light curves for evidence of transiting planets (including disintegrating examples) from the TESS data set.

G011290 Targets

Hot Jupiters are complex systems to study because they are coupled to their host stars. The next step in our understanding of gas giant exoplanets will come from the discovery and characterization of transiting cold Jupiters . We conducted a transit survey from Antarctica and identified transit candidates with long orbital periods. We propose to use the TESS mission to confirm these planets. Because of the long transit durations and sparse transit events, TESS is uniquely suited to these observations. In addition, these objects are close to each other so full frame images will contain all of them. This program should yield the discovery of several transiting cold Jupiters that are suitable to characterization and possibly of other aligned transiting planets in these systems.

G011291 Targets

TESS will observe over 85% of the sky in Full-Frame Images (FFIs). The overlap of sectors near the ecliptic poles provides ~350 days of coverage in the Continuous Viewing Zone (CVZ). This is a valuable place to search for planets due to the long baseline. Over 100,000 stars on the Candidate Target List in the CVZ will not have 2-min data, some these will host observable transiting exoplanets. We will discover over 200 planets in the CVZ using FFIs, and swiftly add them to the 2-min target list as ToOs. The new 2-min data, combined with FFIs, will provide a rich dataset to constrain planet and star properties, search for additional planets, and constrain planet masses through transit timing variations. This work provides a major contribution to the yield of the most valuable planets.

G011294 Targets

Many white dwarfs have been found to have their surfaces "polluted" by remnant rocky bodies from their progenitor's planetary systems. These polluted white dwarfs are our best observational probe of exoplanet interior chemical compositions, which they can reveal with exquisite sensitivity. However, without a good understanding of the origins of white dwarf pollution, it is impossible to fully leverage the information about chemical compositions from the pollution on their surfaces. Using TESS we will study the origins and process of white dwarf pollution by identifying transiting disintegrating minor planets on their way to polluting white dwarfs. This will help to properly interpret the information about planetary compositions from the surfaces of white dwarfs.

G011299 Targets

We propose TESS 2-min and 30-min cadence observations of a carefully selected sample of young solar analogs to focus on a single question with fundamental importance to search for life: What is the level of stellar activity in young sun-like stars and how does it impact habitability on rocky planets in the solar neighborhood? We propose to address this question by observationally characterizing and constraining magnetic activity in solar-type stars at various phases of their evolution. The proposed TESS observations are part of a large multi-wavelength, multi-observatory campaign where the complete data set will allow us theoretically reconstruct space weather properties including coronal XUV and electromechanical fluxes from winds in solar analogs with ages spanning between 0.13 to 2.5 Gy

G022003 Targets

We intend to obtain very high precision light curves of a sample of detached eclipsing and spectroscopic binaries, which we have been monitoring spectroscopically for the last few years within the Comprehensive Research with Echelles on the Most interesting Eclipsing binaries CREME) project. The light curves will be combined with our precise radial velocity (RV) measurements in order to obtain accurate and precise, absolute stellar parameters. This is a continuation of a successful Cycle 1 proposal.

G022010 Targets

Gravitational Lensing by massive ellipticals sometimes magnifies a distant galaxy as multiple clear arcs. A supernova in the distant (source) galaxy would start its light curve at different times in each lensed image thanks to a light path delay of the order of days. This light path delay is a direct measure of the Hubble constant: H0. There is currently significant tension between H0 from SNIa and CMB measurements. We propose to look for lensed supernovae in TESS 30 min images in 1300 known strong galaxy-galaxy lenses. Odds are reasonable that one will be observed (~30%). At minimum, we will obtain an upper limit to the supernova rate in these distant galaxies. Once a supernova is detected, it will independently constraint on the Hubble constant.

G022011 Targets

TESS combination of wide field of view, long total integration times and sampling may make it potentially near ideal for the detection of low-surface brightness features around nearby galaxies. The fraction of stars in the stellar halo of galaxies is a direct test of LambdaCDM galaxy formation models. The low surface brightness halo around nearby galaxies has proven to be observationally challenging from the ground. We propose a pilot project to combine the 30min exposures at the position of nearby edge-on spiral galaxies and model their light distribution to map the halo component. Challenges include combining the TESS imaging data, subtracting foreground stars and diffuse zodiacal light.

G022012 Targets

Despite their proximity and prevalence, we do not understand the distribution of spots and active regions on M dwarfs. TESS provides a unique opportunity to obtain uniform, high cadence photometry for hundreds of bright M dwarfs with known rotation periods, and enables simultaneous ground-based spectroscopy. We will use these data to investigate the origin of scatter in the rotation--activity relationship for M dwarfs. Namely, we will test for the existence of a tight relationship between the amplitude of photometric variability and magnetic activity as measured by H-alpha. This proposal will support our measurement of rotation periods and photometric amplitudes using the TESS data.

G022017 Targets

We propose to observe a sample of white dwarfs and subdwarfs to search for rotationally modulated variations and to detect the variations of rotational period. The derived data will improve our knowledge of the rotational period distribution of white dwarfs providing additional test of evolutionary models. The detection of rotational light variability connected with accretion of debris can provide information about the structure of planetary and asteroidal system around white dwarfs. Light variability of hot subdwarfs could serve as a proxy for the presence of the magnetic field.

G022020 Targets

The rotation, internal structure, mass loss, and binarity of post-main-sequence massive stars are all parameters that are poorly defined and difficult to measure. However, these traits directly influence the evolution and final fates of massive stars, determining their radiative, nucleosynthetic, and kinematic impact on their surroundings. We propose to utilize TESS to simultaneously search for signs of rotational modulation, pulsations, stochastic variability, and more in a sample of red and yellow supergiants, luminous blue variables, and Wolf-Rayet stars. A high-cadence space-based photometric survey of such a large sample that traces variability across the upper HR diagram is unprecedented, and will yield new insight into the behavior of these stellar behemoths.

G022024 Targets

We will maximize TESS s potential as a stellar rotation mission by measuring rotation periods up to at least 60 days from TESS's 27 day single-sector light curves by training a machine learning method (the Cannon) on the light curves of stars in the Continuous Viewing Zones (CVZs). The Cannon is a simple, interpretable method which learns the relationship between stellar parameters and stellar brightness variations. It propagates stellar parameters learned from high fidelity data to poorer quality data, so this approach is ideal for TESS where there is a limited number of long light curves (CVZ stars) and a large number of short light curves (single-sector stars). We will provide a catalog of 500,000 rotation periods for FGKM main sequence dwarfs.

G022026 Targets

We propose to obtain FFI light curves of the 101 brightest blazars observable in Cycle 2, and use them to see if the two classes of blazars (Flat Spectrum Radio Quasars and BL Lac Objects) emit variable optical light via the same physical processes in their relativistic jets. TESS will separate out individual flares, which last a few hours to a few days, and track fractal-variable emission. For three blazars near the north ecliptic pole, we will measure the incidence of flares and the overall fraction of time spent in high and low states for a full year. Our targets are gamma-ray blazars or candidate gamma-ray blazars, including BL Lac, 3C454.3, Mkn 421 and Mkn 501. This proposal and our Cycle 1 proposal provide a complete magnitude-limited blazar sample in the TESS-accessible sky.

G022027 Targets

Metallic-line A (Am) stars show abundance anomalies produced by diffusive settling/radiative levitation which also should reduce the He abundance in the pulsation driving region and inhibit pulsations. Nevertheless, many Am stars show gamma Dor, delta Sct or roAp pulsations, and some show magnetic activity, spots, and flares. Neither the pulsation driving mechanism, nor the origin of the magnetic fields or abundance anomalies are well understood. We request 2-min cadence observations of Am stars having detailed spectroscopic abundance determinations to detect or rule out pulsation frequencies, including those above the Nyquist limit of 30-min cadence full-frame images. This combination of constraints is needed to understand the complex behavior of stars in this region of the HR diagram.

G022028 Targets

We propose 2-min-cadence observations of 1346 white dwarfs visible in Cycle 2 of the TESS mission. Our primary objective is to search these white dwarfs for transits of remnant planetary systems; transits of Earth-sized white dwarfs are likely to be very deep but also very short, just a few minutes, requiring high-speed observations. Our proposed observations will also enable asteroseismology of a large sample of known and high-likelihood pulsating white dwarfs, continuing the space-based revolution into the interiors of pulsating white dwarfs. From both asteroseismology and spot modulation of magnetic white dwarfs we will significantly expand the number of white dwarfs with measured rotation rates, placing strong constraints on the endpoints of angular momentum in stars.

G022029 Targets

We propose to continue a Cycle 1 program to obtain rotation periods for low-mass Hyads, and to extend it to obtain periods for members of Coma Ber. As the closest open cluster, the Hyades is a critical benchmark for stellar astrophysics. By contrast, Coma Ber, which is co-eval and not much farther away, has been far less well studied, principally because its membership has been challenging to establish. Expanding the number of stars in these two clusters with measured rotation periods is essential for calibrating the relationship between age, rotation, and magnetic activity for low-mass stars. We wish to observe a total of 435 members across these two clusters. Most of these stars have yet to be targeted by time-domain photometric surveys; pre-Gaia, most were not associated with a cluster.

G022030 Targets

We propose to investigate the evolution of helium in the local solar neighborhood, in particular the (Delta Y/Delta Z) relation, using asteroseismic data of stars in the TESS Continuous Viewing Zone (CVZ). The helium abundance is one of the most poorly constrained inputs needed to construct stellar models, but it strongly affects a star's structure and subsequent evolution. Helium cannot be detected in the photosphere of most stars. Asteroseismology allows us to determine the helium abundance in the outer convection-zone of stars indirectly by modelling stellar oscillation frequencies, and directly by looking at the acoustic glitch signal of helium ionization. Stars in the TESS CVZ will allow us to study the (Delta Y/Delta Z) relation. Our target list has 204 stars in the northern CVZ.

G022031 Targets

Blazars are active galactic nuclei exhibiting extreme variability on different time scales, down to minutes. Their emission is dominated by non-thermal radiation from a relativistic jet pointing toward us, with consequent Doppler beaming. We propose 2 min cadence observations of a small sample of optically and gamma-ray bright blazars to investigate their variability on the shortest accessible time scales. We selected 20 sources with TESS mag less than 16 and TESS observations spread over all Sectors and Cameras. We will analyse TESS light curves with time series methods to infer the most plausible scenarios for blazar variability. Supporting observations by the WEBT Collaboration and the Fermi satellite will maximize the scientific return.

G022032 Targets

Decades of observations from the Mount Wilson and Lowell surveys identified magnetic activity cycles in many of the brightest stars in the sky. These unique data help to place the solar cycle in context, but the fundamental stellar properties still have large uncertainties. To better characterize the evolution of stellar cycles, we propose to determine asteroseismic masses and ages for a sample of late F- and early G-type stars with existing magnetic activity time-series. Rotation is thought to be a key ingredient in stellar dynamos. With TESS we can also obtain measurements of rotation for F-type stars. These observations will allow us to test the recent suggestion that magnetic dynamos are disrupted in middle-aged stars, and that stellar cycles grow longer as stars age and rotate slower.

G022033 Targets

Robust detrending of TESS light curves has been a standing issue; in addition to the pipeline-produced Pre-search Data Conditioning (PDC), a plethora of other methods, general and dedicated, has been proposed for space-based photometry of Kepler, K2 and TESS. In this proposal we aim to utilize a novel detrending option that is based on using periodic signals in lightcurve timeseries to derive a comprehensive detrending map for the entire TESS-observed sky. We discuss the basic principles, demonstrate its use on a synthetic case and on an eclipsing binary TIC 141770299, and compare its performance to the SAP, PDC and TASOC-detrended lightcurves.

G022035 Targets

In 2018-19, HST s Cosmic Origins Spectrograph (COS) is carrying out a far-UV survey ("EclipSS") of 49 nearby solar-type (F2-K2) dwarfs, located in the ecliptic polar caps. These areas are favored by two important missions: current TESS (photometry/exoplanets) and upcoming eROSITA (X-ray all-sky survey). EclipSS targets were chosen to be isolated, bright enough for TESS and eROSITA, but not too bright for super-sensitive COS. FUV emissions and X-rays trace stellar activity, for which TESS can provide supporting rotation periods, flare frequencies, and seismology. Multiplexed sample will provide unprecedented view of the magnetic engine - the Dynamo - at the heart of the activity, which among other things can impact exoplanets and their habitability.

G022038 Targets

Starspots and flares reveal information about the evolution of photospheric structures and stellar magnetic fields. In stars analogous to the young, rapidly-rotating, active Sun, we do not yet understand the links between these phenomena that have implications on the environment in which the Earth formed. Using the high-cadence, high-precision observations of TESS, we propose to investigate the activity of the brightest active stars in the northern sky. We will study flare rates and energies, as well as starspot evolution and characteristics. We will also study correlations between flare occurrence times and starspot locations. Our results will vitally improve our understanding of stellar magnetic fields on stars with internal structures and rotation rates similar to the young Sun.

G022039 Targets

The objective of this TESS Cycle-2 proposal is to determine accurate relationships to convert M dwarf absolute magnitudes and rotational periods to stellar masses and radii. We will achieve this objective by searching for, discovering and characterizing new low-mass stellar eclipsing binary stars (EBs) in the TESS full-frame images (FFIs), and we propose 36 known EBs for 2-min-cadence observations. The proposed mass-radius-luminosity-rotation relationship is critical for accurately measuring the radii and equilibrium temperatures of the hundreds of transiting extrasolar planets TESS is expected to discover orbiting M dwarfs. We expect to discover thousands of new EBs in the full-frame images. The 36 known EBs proposed for 2-min-cadence observations are bright objects with existing radi.

G022040 Targets

Interferometry makes wide-ranging science possible, from measuring fundamental stellar parameters to imaging stellar surfaces. Interferometric calibration stars are ideally unresolved, nearby on the sky, and of similar spectral types and luminosity classes to the science target. However, this is not always possible, and concessions must be made. The presence of brightness variations across their surfaces could cause calibration issues, affecting the science targets. With TESS observations, these calibrators will be examined for any variations that could affect their suitability as interferometric calibrators. The impact of the variations on the interferometric observables will be determined. Improving the quality of calibrators will improve the science results and effects on astrophysics.

G022042 Targets

The TESS flux time series data provides a wealth of information which will lead to innumerable astrophysical discoveries. An obstacle to these discoveries is the instrumental artifacts in the data sets. Compromises are always made when generating a single set of TESS light curves for export. Ideally, custom cotrending would be performed for each separate research project on each separate light curve and tuned specifically to the signals desired. We propose here to develop a general purpose publicly available tool to allow TESS data users to perform their own TESS pipeline-like correction providing to the user community a dearly needed tool to interpret and utilize the data provided by the mission.

G022045 Targets

We propose an ambitious campaign for extracting granulation parameters and asteroseismic parameters for large samples of evolved stars in the TESS fields. Even with the minimum 27 day baseline we estimate that up to 2.3 million targets could have at least some measurable asteroseismic parameters, covering a substantial fraction of the Galaxy and permitting unprecedented galactic archeology studies. We justify our predicted yields and present a comprehensive analysis and follow-up plan to take advantage of the unique capabilities of TESS as a stellar population discovery engine.

G022046 Targets

The strange flux-dips found in Kepler data of KIC 8462852 have given rise to one of the most enigmatic astronomical discoveries in recent time, as no satisfying explanations for these dips have been found yet. We request 2 minute cadence observations of the star with the TESS satellite in order to explore the star's variability. We will use the TESS time-series to 1) perform asteroseismic analysis to search for coherent delta-Scuti like pulsations and 2) search for new dipping events, the next possibly occurring during the TESS observation window. We will augment these TESS data with coordinated multi-wavelength observations contemporaneously planned at ground-based observatories and with the SWIFT satellite.

G022047 Targets

The analysis of transiting planet and eclipsing binary light curves depends on understanding aspects of stellar structure, e.g. limb darkening, surface temperatures, granulation, spots, and flares, that are not adequately modeled for cooler stars. We have a practical full frame image stack analysis pipeline for the identification of unique stellar variability which provides input to subsequent ground-based followup. Our work will result in an understanding of the rich variety of temporal stellar variation in the TESS data as it is acquired, enable additional measurements for sectors seen only once, and improve characterization of the host stellar environment of newly discovered transiting exoplanets.

G022052 Targets

We propose to acquire 2-minute cadence photometry of 29 bright stars near the northern ecliptic pole. We are simultaneously monitoring these stars in radial velocity (RV) using the Automated Planet Finder (APF). TESS's long-baseline lightcurves for these stars increase the period sensitivity to transits and provide a probe of stellar activity, which will improve models of the APF RVs and aid in the discovery of terrestrial exoplanets. The combined TESS-APF observations also offer unique sensitivity to stellar mirages, brightening events caused by refraction in a planet s atmosphere. We have already identified two exoplanets that are excellent candidates to exhibit mirages. If TESS observations confirm mirages, it will open a new window to exoplanet atmosphere characterization with JWST.

G022053 Targets

The field of exoplanets has progressed beyond planet detection to characterization of planetary systems. This includes planetary structure and atmospheres, system architectures, orbital dynamics, and the studies of exoplanet host star properties. The characterization of known exoplanets is therefore a critical component of the on-going expansion of the field. This proposal aims to ensure that all known northern hemisphere exoplanet host stars are included in the TESS target list. The three main science goals of the observations are: (a) observations of potential transits and phase variations, (b) refined transit ephemerides enabling spectroscopic follow-up with future space-based facilities, and (c) detailed stellar properties through astroseismology modeling.

G022055 Targets

The "redback" systems are now challenging the evolutionary link between NS LMXBs and rotation-powered radio pulsars. The study of the long-term behaviour of the optical emission in systems in either states has the great potential to unveil those prone to perform state transitions, to dissect the role of the intra-binary shock between the pulsar and companion winds, and to determine the condition for disc formation and disappearance. We propose to observe at 2-min cadence a sample of 4 redbacks of which 3 are currently in a rotation-powered state and one in an accretion disc-state. The observations will probe the effects of the intra-binary shock in the heated-induced wind of the companion for the 3 former systems, and the long-timescale accretion-induced variability in the latter system.

G022056 Targets

Detailed studies of the Sun have shown sunspots and solar flares are closely correlated. It is widely thought that the rotational modulation seen in late type dwarfs is due to a dominant starspot rotating into and out of view. We therefore naively predict that flares would be observed more often at rotation flux minimum. However, our observations using Kepler/K2 and now TESS have shown that flares show no preference for rotation phase. This makes us reassess how large scale magnetic fields are generated on low mass, fully convective stars. Here we bid for 2 min cadence observations of 155 low mass stars in TESS Cycle 2. With this increased sample we will search for correlations between activity, spectral type, rotation period and age.

G022057 Targets

Recent progress has been made on horizontal branch and post-flash physics using MESA models. Obtaining >100 sdBV stars with TESS data will allow us to completely populate the He-fusing region of the HR diagram. This is necessary to break mass/evolutionary degeneracies. TESS seismology will provide core masses and internal structure across differing evolutionary paths. Our proposal has 3 main objectives: 1) determine evolutionary core mass sequences of horizontal branch stars. 2) Determine angular momentum evolution across the helium flash and between interacting binaries; and 3) characterize radially differential rotation as a probe of core-envelope interactions. K1 & K2 showed us how, TESS data will complete the process by providing statistically complete samples.

G022058 Targets

We will use the Montage Image Mosaic Engine, a mature Open Source toolkit, to create co-added image mosaics of all the FFIs of the southern hemisphere, released in Mission Year 1. We will study the optimum way of rectifying images for the effects of image artifacts, and the mosaics will be ready for cutting-edge research on diffuse extended emission; e.g. derivation of the halo mass profiles of galaxies, and identification of galaxy cannibalism leftovers. We will also create dedicated mosaics for import into the World Wide Telescope and into HiPS-complaint visualizers (e.g. Aladin and ESASky). The data products will be made freely available through the NASA ExoFOP-TESS archive. All dedicated software will be made available as part of the Montage distribution.

G022059 Targets

We propose to observe a sample of 24 gamma-ray blazars with TESS, combining FFI and 2-min cadence data. TESS light curves, along with VLBI and polarimetric monitoring that we perform for the sample, will allow us to analyze properties of turbulent plasma in jets of blazars, which have yet to be systematically explored. Inclusion of TESS light curves in our decade-long photometric observations of each blazar is crucial for construction of power spectral densities and determining their characteristics. We will perform a correlation analysis between TESS and Fermi LAT gamma-ray light curves with unprecedented accuracy, providing information on the relative location of gamma-ray and optical emission regions in blazars.

G022061 Targets

The unprecedented high precision of parallaxes in Gaia Data Release 2 (DR2) reveals a new feature in the lower main sequence of the H-R Diagram (HRD). Theoretical models predict that M dwarfs in this narrow transition zone are in a pulsating phase because of the mixing of 3He during the merger of envelope and core convection zones. We expect that these pulsating stars will show high photometric variability in the form of flares because of unstable magnetic configurations. Here we request to add 107 carefully selected targets in addition to those already being observed by TESS core science targets that lie in this region in the HRD. We propose to acquire short cadence, high precision TESS photometry to study stellar variability levels for these stars and will provide the first systemati.

G022062 Targets

Eclipsing binary stars (EBs) have served as principal gauges of fundamental stellar properties: the benchmark-grade systems allow an accuracy in masses and radii to exceed 2%, in turn providing stringent constraints on stellar evolution models. This is a multi-faceted proposal that builds on three principal aims: (1) extract known EB light curves from full-frame images; (2) run a search for unknown EBs within the full-frame images and extract their light curves; and (3) acquire 2-min cadence observations for a priority-sorted list of EBs that will serve as calibration standards, galactic population tracers and follow-up of well-studied, important systems, especially those observed by Kepler.

G022063 Targets

A comprehensive census and understanding of exoplanetary systems requires the discovery and characterization of planets orbiting stars of different masses. Out of the ~3600 confirmed exoplanets known to date, only ~5% orbit stars more massive than 1.4 M_Sun and just a few have been found to orbit intermediate mass, main sequence A-type stars (7500 < T_eff < 10,000 K; 1.4 M_star < 2.2 M_Sun). Focusing on bright stars and thanks to its all-sky coverage and superb photometric precision, TESS has the best chances to find planets transiting bright early-type stars. We request here TESS observations of lambda Bootis stars in the Northern ecliptic hemisphere to complete our sample of these unique target stars and to test the hypothesis that their chemical peculiarities are connected to planets.

G022064 Targets

The bright Be star HD6226 has been a target of a recent intensive observational campaign, and has built lost a disk four times during this time frame. The cause of the disk-building episodes in Be stars remains unknown. However, this star has shown strong evidence of a non-radial pulsational mode in the optical spectra we have collected. While our data cannot identify the pulsational mode, other Be stars observed with missions such as MOST have revealed that there is a rich pulsational spectrum beyond the few modes identified from the ground. As such, two-minute cadence observations with TESS should allow us to understand the seismic structure of this Be star. Such an understanding could elucidate the underlying physics that cause some rapidly rotating B stars to form disks.

G022065 Targets

The evolution of planetary systems after the main sequence is largely unknown and no planets around isolated White Dwarfs (WD) have yet been detected. Some show evidence of metal pollution or gas and dust discs indicating that planetesimals and even dwarf planets up to the size of Pluto that strayed too close to the WD and have subsequently been tidally disrupted. However there is only one known system where this can actively observed, WD1145+017. Such objects would only survive a star s evolution to a WD at distances greater than at least 1AU implying these objects may have been scattered by unseen planets. We propose to observe all WDs with magnitudes <16.5 with similar evidence of planetary systems to search for further examples of ongoing tidal disruption of planetesimals.

G022069 Targets

Ages are an incredibly important attribute of an isolated star. However, ages of isolated cool dwarfs are notoriously difficult to measure. Here we propose a program to study with TESS a sample of 1100 bright stars with coeval white dwarf (WD) companions in wide, common-proper-motion binaries. Hundreds of the WD companions in our systems are cooler than 6000 K, with total ages exceeding 5 Gyr -- very few field stars bright enough for TESS have such old, well-constrained ages (nearby, old clusters such as Ruprect 147 and M67 are not older than 4 Gyr). With existing observations and techniques, we can estimate the total ages of these WDs to better than 30% across all ages present in our Galaxy. This dataset will be a benchmark sample to constrain gyrochronology, age-activity relations, and .

G022070 Targets

Astronomers know of only 19 transiting brown dwarfs. This means that only as many brown dwarfs have well-characterized radii and masses. This limits our ability to test substellar evolutionary models and build a fundamental understanding of this population of objects between planets and stars. Seven brown dwarf candidates discovered by radial velocity surveys stand to have transit searches conducted on them and six confirmed brown dwarfs have poorly constrained radii derived from their original light curves. We propose to use TESS to conduct transit searches of these 7 brown dwarf candidates and to obtain modern, high-cadence light curves of these 6 confirmed brown dwarfs to improve the radius uncertainties on them.

G022071 Targets

Accretion is responsible for the growth and evolution of most objects in the Universe, yet many unanswered questions remain in accretion disk physics. We propose to observe a sample of 188 accreting compact objects (comprising a mix of accreting white dwarfs, neutron stars, and stellar-mass black holes) at 2-minute cadence with TESS. This is a continuation of a Cycle 1 proposal to probe into the long- and short-timescale accretion-induce variability for many object types, allowing for both studies on individual objects and ensemble analysis to compare accretion variability across different accretor types. We will also co-ordinate X-ray observations to be simultaneously performed on some targets, allowing us to study X-ray/optical time-lags on week timescales.

G022076 Targets

M dwarfs account for 75% of all stars, yet key stellar properties remain uncertain, notably their magnetic activity and rotation periods. For the coming decade, the only spectroscopically-accessible temperate, terrestrial worlds will be the ones that transit the closest mid-to-late M-dwarfs, which are the most easily studied. We propose to gather TESS 2-minute cadence observations of the volume-complete sample of mid-to-late M dwarfs within 15pc. Short cadence is essential to determine the flare morphologies; we will also measure rotation periods, and precisely measure radii for new-found eclipsing binaries. We will combine the TESS light curves with our ongoing high-resolution spectroscopic survey and existing astrometric data to yield a legacy dataset of our closest stellar neighbors.

G022077 Targets

Many white dwarfs have been found to have their surfaces "polluted" by remnant rocky bodies from their progenitor's planetary systems. These polluted white dwarfs are our best observational probe of exoplanet interior chemical compositions, which they can reveal with exquisite sensitivity. However, without a good understanding of the origins of white dwarf pollution, it is impossible to fully leverage the information about chemical compositions from the pollution on their surfaces. Using TESS we will study the origins and process of white dwarf pollution by identifying transiting disintegrating minor planets on their way to polluting white dwarfs. This will help to properly interpret the information about planetary compositions from the surfaces of white dwarfs.

G022078 Targets

"Superhumps" are periodic photometric waves in the light curves of compact stars accreting through a disk. They seem to arise from eccentric and wobble instabilities at the 3:1 resonance in accretion disks, and always produce a periodic signal several percent displaced from the orbital period. Several harmonics and sidebands of that primary signal are probably also present, but have never been clearly mapped out, due to inevitable interruptions in ground-based coverage. Our four targets for TESS coverage are the only cataclysmic variables which show both types of precession (apsidal and disk-wobble), and cry out for very long time series, which will elucidate the precise period structure, and relation between the two frequencies.

G022080 Targets

We have identified 609 of these stars with significant RV histories at Keck/HIRES observable in TESS Cycle 2 with priorities currently set to <1. Here, we propose that these stars receive 2-minute cadence observations with TESS. The specific reasons are as varied as the stars themselves, but the unifying theme is that this is our only chance to ensure that some of the most comprehensively-observed stars in the sky, with 20-year RV histories, receive TESS-quality high-cadence photometry, even if only across 27 days. Some systems will inevitably host as-yet undetected transiting planets, for which we will have pre-covery RV observations to immediately help place constraints on Mp.

G022082 Targets

Period-age relations may be the most powerful tool for stellar age determination in the TESS cool dwarf sample. In order to realize the potential of this tool, we must understand how it behaves as a function of stellar type, age, and evolutionary state. We will search for rotational modulation in ~200,000 Northern Continuous Viewing Zone stars in the TESS Full-Frame Images, and in ~2000 Asteroseismic Target List stars spread across the northern sectors. When combined with the Southern fields, we aim to increase the existing rotation period sample by a factor of ~4 and diversify the stellar populations we probe. With this sample we can disentangle the interplay among physics, stellar populations, and observational bias to hone period-age relationships as a tool.

G022084 Targets

Individual theories of planet formation and migration struggle to reproduce the characteristics of the known giant planets, so it is likely that multiple mechanisms shape this population. The orbital eccentricities of hot Jupiters hold clues to their formation and dynamical evolution. The TESS mission is built to exploit the valuable science of transiting planets orbiting bright host stars, finding suitable targets for precise eccentricity measurements. We propose for 2-minute cadence TESS observations of a set of high-quality transiting giant planet candidates identified from the KELT survey. The goal of this project is to combine the high photometric precision from TESS with up to a 15 year long baseline from KELT to confirm and characterize (obtain precise eccentricities) new planets.

G022085 Targets

Every month, TESS data must be meticulously combed for the weakest transit signals. While a daunting task for humans, this is an exciting opportunity for deep learning, which is a state-of-the-art machine learning tool designed to solve this problem of rapidly and reliably classifying large samples of weak signals in noisy data. We propose to use deep convolutional neural networks to rapidly classify the thousands of TCEs identified every month by the TESS Science Processing Pipeline as either exoplanets or false positives. Furthermore, we propose to develop methods that assign absolute probabilities with associated uncertainties to each exoplanet classification, which will be extremely useful for prioritizing follow-up as well as improving exoplanet statistics.

G022088 Targets

Being the lowest mass and lowest metallicity main-sequence stars, M subdwarfs offer an extreme environment for planet formation. However, despite the lack of mass and metals available to form large cores capable of accreting gas, recent results indicate that smaller, terrestrial planets may still form around M subdwarf stars. We propose to search for these planets around a sample of 337 subdwarf stars with short-cadence data. By simulating the observation of this sample and injecting planets using statistics for early M dwarfs, we predict the detection of two planets in this effort. The detection of even a single planet orbiting an M subdwarf star would dramatically impact our understanding of planet formation and further reinforce that terrestrial planets are common in the Universe.

G022090 Targets

We propose to observe ~24 new supernovae (SNe) jointly with TESS, Swift, and the Las Cumbres Observatory, a robotic network of telescopes with imagers and spectrographs distributed in latitude and longitude so that instantaneous and uninterrupted observations are possible. These will be added to the ~16 SNe already observed with TESS+LCO, which also have multicolor lightcurves and spectroscopy from the Global Supernova Project. With these data we can probe fast transients and rarely seen phenomena in SNe that reveal their progenitors: shock breakout and cooling, collision of supernova ejecta with a companion star, and interaction with circumstellar material cast off in the last violent pulses before explosion. The TESS data will reveal the timing of the explosion and ~hour cadence phenom

G022092 Targets

The primary aim of this proposal is to calibrate relationships between variations in several photometric, asteroseismic, and spectroscopic stellar activity indicators using TESS photometry and contemporaneous high-fidelity spectra obtained with the EXtreme PREcision Spectrograph. Recent solar evidence suggests that these activity indicators offer complementary perspectives of physics at stellar surfaces. This investigation connects efforts to understand surface contributions to asteroseismology with efforts to disentangle photospheric contributions to measurement errors in extreme precision RV data. Both of these are major open problems.

G022099 Targets

With space asteroseismology we can measure the internal rotation of evolved stars. Subgiant stars are especially valuable because we can also measure their surface rotation, which is difficult or impossible for more evolved stars. Prior studies have given us strong evidence for cores rotating faster than their surfaces, but only for small subgiant samples. We request observations of 227 high-priority subgiant stars in the northern continuous viewing zone. A one year time series will yield high quality data capable of measuring internal rotation, and we have arranged complementary ground-based data to fully characterize these important targets. This powerful sample will permit tests of gyrochronology and stellar angular momentum evolution theory, and it has other broad applications.

G022100 Targets

In an era of large galactic spectroscopic surveys, it is necessary to have a sample of stars that can be used for testing the performance and accuracy of the provided datasets: the benchmark stars. Benchmark stars must be stars with atmospheric parameters measured with great precision using different methods: spectroscopy, interferometry, and asteroseismology. At the moment only a sample of 36 benchmark stars is provided. With this proposal we aim at obtaining seismic parameters for a sample of bright red giants, that already have spectroscopic and interferometric measurements. At the completion of this project the number of spectroscopic benchmark stars will be doubled.

G022101 Targets

By covering a solid angle nearly 400 times larger than a single Kepler/K2 field, photometry from TESS Full Frame Images (FFIs) is expected to revolutionize time-domain astronomy over the coming years. However, light curves from FFIs will not be a standard TESS data product, and hence the success of science from FFIs relies on efforts by the community. Here we propose to continue the development and application of an end-to-end FFI photometry pipeline, producing analysis-ready light curves for all FFI sources. Using powerful computing resources and software developed through community workshops within the TESS Asteroseismic Science Consortium, the light curves produced in this program will enable a vast array of science investigations across stellar astrophysics and exoplanet science.

G022102 Targets

Stars undergo dramatic changes as they evolve into red giants, providing a unique opportunity to study the response of exoplanets to changing irradiation, tides and mass loss in a manner that is not possible on the main sequence. We propose to use TESS full-frame images to detect and characterize giant planets transiting red-giant stars. Our program will combine transits, asteroseismology and radial velocities to address key questions such as (i) the occurrence of giant planets as a function of stellar mass, metallicity and evolutionary state and (ii) the mechanism(s) responsible for the inflation of hot Jupiters. Our program is the first near-all-sky survey that systematically combines asteroseismology and transit photometry to precisely characterize exoplanets orbiting evolved stars.

G022103 Targets

Asteroseismology is a unique observational tool to probe the interiors of stars, and a benchmark method to determine surface gravities, masses, radii and ages of solar-type stars. Here we propose TESS 2-minute cadence observations that will quadruple the current sample of solar-type stars with asteroseismic data, providing fundamental parameters for thousands of stars. The sample will allow us to (i) constrain poorly understood physical processes in stellar models such as convective energy transport,(ii) precisely characterize exoplanets through their host stars and (iii) investigate mode excitation for hot solar-type stars. Our benchmark sample will also enable a wide range of ancillary science including fundamental calibrations of stellar granulation, spectroscopy, and gyrochronology.

G022104 Targets

In this proposal, we aim at putting constraints on the Milky Way ISM lithium chemical evolution. It has been proposed that the puzzling lithium decrease at super-solar metallicities could be caused by old stars, originating for the inner parts of the discs, depleting their lithium during their time-travel (Guiglion et al. 2019). Using TESS light curves of 15 selected dwarfs stars (6 of them are super-solar), we plan to derive precise masses, radius and ages, and well as atmospheric parameters and refined lithium abundances from ESO HARPS spectra. If such metal-rich stars are confirmed to be old, this would reinforce the fact that they migrated from the inner-disc, giving additional constraint to the lithium ISM decrease.

G022105 Targets

The understanding of the early phases of our Galaxy, the characterization of the chemical enrichment timescale, and the nature of the first stars is encoded in the abundance pattern and age (and mass) of metal-poor halo stars. To date, very few metal-poor stars have an age determination, but the situation is changing thanks to the availability of seismic constrains on the masses of solar-like oscillating giants and to the tight age-initial mass relation they adhere to. Here we aim at determining precise ages for about 150 metal-poor stars in the Halo, for all the proposed targets we have already high-resolution spectra. To this aim we will combine seismic information obtained with TESS to the precise atmospheric parameters and abundances coming from spectroscopy.

G022106 Targets

Stellar ages typically have large errors (~4 Gyr), but with Kepler it was possible to estimate ages with better precision through asteroseismology, yet their precision depends on how precisely we know the temperature and metallicity of stars. Different burning problems in stellar physics, such as the apparent rapid rotation and flat magnetic activity of old stars, depend critically on precise ages. We take advantage of a sample of solar twins with precise stellar parameters, to estimate precise seismic ages with TESS, to assess if gyrochronology is still valid in stars around solar age, verify the decrease of stellar activity with age and calibrate the decay of stellar lithium with age. Finally, our improved age calibrations will contribute to constrain ages of planets discovered by TESS.

G022109 Targets

Planets and their host stars evolve with time, and the first few hundred million years are the most critical. By identifying planets over a range of ages, we can directly observe such changes. K2 greatly expanded our knowledge of exoplanet evolution by observing stars in nearby young associations, enabling the identification of dozens of young planets. We have built on this success by identifying several planets in nearby young moving groups during TESS Cycle 1. Here we propose to extend this program to TESS Cycle 2, taking advantage of the greater diversity of young associations in the northern ecliptic sky. In addition to expanding the number of known infant (<200 Myr) planets, this survey will include stars sufficiently bright for follow-up to measure planetary masses and atmospheres.

G022111 Targets

We propose to analyze the light curves of thousands of known Main Belt asteroids (MBAs) seen by TESS in Camera 1 full frame images (FFI). TESS offers a unique opportunity to study long-period rotators that have strong observational bias from ground-based observations as well as MBAs with small light curve amplitudes. Positions of known MBAs are predictable with the astrometric uncertainty within one pixel in each FFI. Our simulation showed that there will be 5,648 MBAs brighter than +18 magnitude visible for 10 or more days in TESS Camera 1 during its first year of science operations. We estimate that our work will at least double the number of MBAs with known and reliable rotation periods and amplitudes.

G022112 Targets

99% of all stars in the TESS field of view are not observed at 2-minute cadence, but instead only through the Full Frame Images. There is no direct mission support for turning these data into publicly available light curves, searching for planets, or otherwise analyzing these frames. Here, we propose to continue development of the eleanor package for light curve extraction from TESS FFIs. Our open-source package has already been used to find planets and other astrophysical variability in TESS data. We will improve the PSF modeling routines in eleanor to maximize our ability to characterize small signals in crowded fields and our 2-d background models in order to minimize the effects of scattered light from the Earth and Moon.

G022113 Targets

Quasi-periodic oscillations (QPOs) are fundamental properties of both solar and stellar flares. This poses the question of whether common physics produces these signatures, despite the very different size and energy scales. We will use the recently-developed AFINO analysis code to detect QPOs in stellar flares from young, magnetically active M-dwarf stars observed by TESS at 2-minute cadence. We will characterize the properties of both the stellar flares themselves and their associated QPO properties, and compare with those previously determined in the solar domain. This allows us to understand the prevalence of stellar flare QPOs, constrain the relationship between stellar and solar flares, and understand whether the same mechanisms play a role in both regimes.

G022114 Targets

We propose to produce and make public lightcurves for isolated targets in the TESS full-frame images during Cycle 2, and cross-match these to Gaia. The cross-match with Gaia DR2 will allow to explore lightcurves within specific regions of the color-magnitude diagram (CMD), allowing the exploration of specific populations of targets. Our team will visually inspect all targets on the blue side of the Gaia CMD, all targets displaying photometric H-alpha excess emission, and all transients discovered by the All-Sky Automated Survey for Supernovae. Our tool will allow the community to view and download lightcurves, power spectra and locate the position of a given target in the Gaia CMD. By leveraging the Gaia/TESS synergy, this tool will deliver long-lasting legacy value to the TESS mission.

G022115 Targets

To date there have been no studies using asteroseismology to probe the internal transport of chemical elements via atomic diffusion in intermediate-mass stars. We address this shortcoming with a study of slowly-rotating F and B stars using 2-min cadence TESS data to model their p- and g-modes. We complement the TESS data with spectroscopy and Gaia data for our targets. We will compute new grids of stellar evolution models for intermediate-mass stars with atomic diffusion and radiative levitation. Our team has developed a data-driven asteroseismic analysis that enables the calibration of internal transport processes. Our work will result in useful constraints on internal transport processes. Our stellar model grids will be made publicly available.

G022116 Targets

Cataclysmic variables provide the cleanest available natural laboratories to investigate the physics of accretion. The timing capabilities and sensitivity of TESS are well matched to the timescales and amplitudes of accretion variability in these sources. The combination provides an opportunity to test and refine the paradigms of stellar accretion with high-precision, uniform data containing no diurnal gaps. We propose a continuation of our multifaceted observational and modeling program that has the potential to measure the spatial structure of model dependent disk parameters. Like the Kepler/K2 mission, the analysis of TESS observations of CVs will significantly impact our understanding of accretion dynamics and the nature of astrophysical viscosity.

G022117 Targets

We propose to produce, and make public, light curves for all ~100,000 known star cluster members brighter than T = 16 observed in the TESS full-frame images during Cycle 2. The light curves will be generated using an image subtraction photometry procedure which we have adapted to TESS and are currently applying to Cycle 1 observations through GI support. We will search the light curves for transiting planets, expecting to triple the number of transiting planets known in clusters, which will shed light on the timescales for processes in planet formation, evolution, and migration. The public data set will also be a gold mine for stellar astrophysics, including studies of gyrochronology, variability and tests of stellar evolution.

G022119 Targets

We propose to extract and analyze TESS light curves for all 1915 candidate transiting planet systems in the Northern ecliptic sky that have been identified by the HAT ground-based transit surveys, and which are not among the top priority TESS targets. These light curves will be used to confirm and characterize transiting planets, including giant planets around M dwarfs, to look for additional transit signals in the light curves, to check for transit timing variations, and to calibrate the follow-up efficiency of the HAT surveys. We propose for 2 minute cadence observations for 101 targets where high cadence is necessary, the remaining 1814 targets will be analyzed using the full-frame images.

G022121 Targets

The KESPRINT planet team proposes to use TESS 2-minute cadence and FFI data to search for planets in a sample of 25777 stars with sub-solar metallicity. The goal is to determine the planet-formation history of the various stellar populations of our Milky Way Galaxy. These stars are all selected from large spectroscopic surveys, and thus are well understood. We propose the brightest 4245 stars for 2-minute cadence to enable asteroseismic analysis. For the FFI extraction of the remainder, we will use the techniques that we have already developed for CoRoT and K2. We will then search these lightcurves for transiting planets, and will perform follow-up observations and detailed system modeling on promising candidate planets in order to validate and/or confirm the candidates as planets.

G022122 Targets

The roAp stars are rapidly oscillating A-type stars that have strong magnetic fields and extremely high abundances in the rare earth metals. To date, only 69 roAp stars have been discovered. With TESS, we will observe all the known roAp stars and find new ones. The significant increase in sample size and improvement of noise characteristics in the pulsation frequency range will allow our team to: investigate the instability strip and consequently establish the pulsation driving mechanisms; probe the full range of pulsation periods; and determine the occurrence of non-pulsating Ap stars in the roAp star instability region. All the aforementioned results will be used to inform our theoretical models. For roAp star science, TESS offers a whole new ball game.

G022125 Targets

The atmospheres of planets evolve under the influence of their parent star. For planets orbiting within the habitable zone of low-mass stars, these effects can be magnified due to their proximity to the host star. We propose TESS two-minute light curves of the targets that will be observed by the NASA-funded Star-Planet Research CubeSat (SPARCS) to resolve the short-lived flares (typical lifetimes of a few hours), quantify the optical stellar rotational variability, and determine the flare-frequency distribution. There are 7 SPARCS target stars that will be observed by TESS in Cycle 2. The TESS and SPARCS data will provide multi-wavelength flare frequency distributions, rotational modulation, and total flare energies that will enable new scaling laws between the optical and UV.

G022126 Targets

We propose to use TESS to observe thirteen eclipsing cataclysmic variables. The TESS data will be combined with observations of the eclipses from ground-based telescopes from the Center for Backyard Astrophysics. The TESS data will probe the longer-term behavior of these CVs as shown by the Kepler and K2 observations. TESS will examine a broader range of eclipsing CVs than was possible with Kepler or K2. We pursue subtle systematics in the light curves.

G022128 Targets

We propose to discover transiting exoplanets orbiting high-mass stars ($M_star >=1.3M_odot$) from TESS's Cycle 2 full-frame images (FFIs) and measure their spin-orbit alignments (the angle between the stellar spin angular momentum and the planetary orbital angular momentum) via gravity-darkening analysis of the TESS light curves. The proposed work will significantly increase the number of spin-orbit alignment measurements for exoplanets with high-mass, early-type host stars, leading to constraints on the mechanisms for misalignment and planet formation and evolution pathways. We also propose high-cadence observations of Kepler-462b to obtain follow-up information on its dynamic behavior.

G022129 Targets

While TESS will readily obtain ephemerides for short-period planets, it will only detect one or two transits for planets with periods > 13 days. We will using existing ground-based survey photometry from the KELT project to detect and verify ephemerides for single and double-transit TESS detections. Our analysis demonstrates that KELT photometry can confirm ephemerides for planets Neptune size and larger with orbital periods as long as a year, and therefore across a wide range of equilibrium temperatures. We will apply this procedure to all TESS 2-min and FFI light curves that show single and double transit events, and release ephemerides for all detections to the community. These results can be used to help confirm TESS candidates and to schedule detailed atmospheric observations.

G022133 Targets

Only for the brightest stars can complementary observational techniques (eg astrometry, asteroseismology, and interferometry) be combined. So far, these stars have rarely been observed with high-precision, high-cadence photometry from space telescopes such as Kepler/K2 due to saturation. Our goal is to perform 'halo' photometry of all naked-eye stars in TESS to obtain high-precision 2-min cadence light curves. The software and data produced will enable science across stellar astrophysics and exoplanets: refining asteroseismic scaling relations, detecting transiting planets for JWST, and studying stellar pulsations and binary stars. Our proposal is the only program capable of providing precise and low-pixel-cost 2-minute cadence photometry of the brightest and most valuable TESS targets.

G022135 Targets

Through the chemical enrichment of their environment, massive stars play an important role in many fields of modern astrophysics and largely guide the evolution of the Universe as a whole. While major shortcomings prevail in their stellar structure and evolution theory, asteroseismology provides a promising tool for calibrating their internal properties by studying stellar pulsations which probe different depths of the stellar interior. However, due to the limitations of ground based observational campaigns as well as previous space missions, tight observational constraints have only been achievable for a handful of massive stars. With this science case we aim to remedy this situation by studying 73 O and B stars observed by TESS for at least 3 sectors in the northern hemisphere.

G022136 Targets

The 150 pc volume around the Sun is a laboratory for studying all aspects of star and planet formation. That statement is especially true regarding co-moving, co-evolving young associations. Gaia is revolutionizing our understanding of young groups of stars and TESS is well placed to immediately begin complimenting and enhancing our knowledge of these stellar associations and their planetary systems. For this proposal, our team has recovered 3578 confirmed or high-probability members of young moving groups that will have full frame images. We propose to use these stars to establish the rotational period relation for solar to M dwarf stars across 3.7 Myr (Epsilon Cha) - 750 Myr (Hyades) moving groups as well as confirm candidate members through their fits to the relations.

G022138 Targets

The age rotation relationship provides insight into how stellar winds and magnetic fields evolve. Recent analyses found that spin-down stalls for K and early M dwarfs around 600−1000 Myr, while the age at which mid-to-late M dwarfs begin their spin-down is still unknown. We will take advantage of TESS full frame images to measure rotation periods for both components of Gaia-identified binaries. We will use G dwarf primaries to constrain the ages of the K and M dwarf secondaries. This will enable studies of stalling and convergence in these low-mass stars, improving gyrochronology relations and providing new insight into the stars' magnetic dynamos and winds.

G022141 Targets

Here we propose TESS photometry of known and candidate variable hot subdwarf B (sdB) stars, with an emphasis on eclipsing systems with low-mass companions. From an analysis of the Gaia DR2 flux errors, we have identified a large number of sdB stars with inflated flux errors for their magnitudes, strongly indicative of variability. Follow-up TESS observations of these systems will lead to the discovery of new eclipsing sdB+dM binaries (HW Vir systems), non-eclipsing reflection effect sdB+dM binaries, and even ellipsoidally-modulated sdB+WD systems. In addition to this discovery work, we request TESS light curves of all known variable hot subdwarf binaries in order to improve modeling of their parameters, and to constrain their masses and eccentricities from Roemer delay measurements.

G022142 Targets

TESS will observe ~423 million stars, with |b|>6 deg, over the course of 2 years, but only 400,000, 2-minute-cadence targets will have light curves provided by the mission. During the first year of the mission, we provided high-precision, difference imaging light curves, differenced images, TESS Input Catalog stellar parameters, Lomb-Scargle periodicity information, Box-Least-Squares eclipse information, and basic variability metrics for nearly 50 millions stars observed in the first 4 sectors through an interactive visualization portal. These products have been shown to be as precise as official NASA data products, and have already led to independent community discoveries. This proposal seeks to continue these efforts in the second year of the survey.

G022144 Targets

Quasi-periodic oscillations (QPOs) are potentially valuable tools for studying accretion disks, general relativity, and the environments around black holes. Despite proliferating theories, however, their physical origin is still unknown. Although common in the X-ray light curves of stellar mass black holes, they are frustratingly elusive in active galactic nuclei (AGN). This discrepancy has serious consequences for the universality of accretion across vast physical scales, but may be due only to a lack of suitable AGN light curves. Bolstered by the discovery of the first candidate optical QPO in a Kepler AGN light curve, we request short-cadence observations of two AGN with high-frequency X-ray QPOs, to search for the same signals or their low-frequency counterparts in optical emission.

G022145 Targets

Kepler showed that the transiting exoplanet population is strongly sculpted by atmospheric escape. The best observational probe of escape is transit spectroscopy with H I Lyman alpha. However, neutral hydrogen in the ISM completely attenuates the core of the line even for the closest stars, hiding the key bound region of a planet's exosphere. High radial velocity stars offer a solution, as transit signals will be Doppler shifted out of the ISM's 100\% attenuation zone. We propose to search for large, short-period planets around 264 nearby, bright, high radial velocity stars to find planet candidates that will be suitable for Lyman alpha transmission spectroscopy with the HST. We expect to find ~5 planets, which will likely become benchmark systems for directly probing atmospheric escape.

G022148 Targets

Eclipsing binaries (EBs) provide benchmark measurements of stellar masses and radii that are the foundation of theoretical stellar astrophysics. Large areas of model parameter space remain poorly constrained by observations, however, particularly at low masses and young ages. From the few sources that have been studied in this regime, current models have been unable to simultaneously describe their observed properties (mass, radius, Teff, L). A thorough test of theoretical models requires a sample of EBs that spans both mass and age. TESS will provide the first dataset capable of finding EBs on this scale. We therefore propose for targeted 2-m cadence observations of young cluster and moving group members in which to find and characterize young EBs.

G022149 Targets

Transit Timing Variations (TTVs) have enabled masses and orbits of dozens of transiting exoplanets to be characterized; allowing inferences on planetary compositions and their atmospheric scale heights. TTVs increase in signal strength with orbital period and with the photometric baseline. Transit timing with TESS will constrain the masses of dozens of transiting planets and constrain the architecture of systems where non-transiting perturbers cause TTVs. TESS will reestablish the transit ephemeris of planets with diverging TTV posteriors enabling the efficient follow-up of Kepler TTV systems by ground- and space-based observatories into the JWST era.

G022150 Targets

The Kepler data set enabled us to identify and characterize nearly 3000 eclipsing binary systems. Thanks to the continued high-cadence observing, Kepler also allowed for measuring eclipse timing variations (ETVs) across the entire EB catalog to identify triple and higher-order systems. Unfortunately, Kepler's finite nominal mission limited both our precision in the measured orbital periods and also our sensitivity to detecting wider companions from ETVs. TESS provides the perfect opportunity to extend this science as it is observing the same field in the sky within a relatively close time-frame as Kepler; this will enable us to double the time-baseline of Kepler, therefore doubling our sensitivity to these systems.

G022152 Targets

We propose to use the TESS 30-minute full-frame images (FFI) to investigate the rotational dynamics and temporal activity of comets that serendipitously appear in the TESS fields of view, monitoring as many as 50 comets in the 26 sectors from years 1 and 2. Our primary focus is on rotation and changes in the spin state of the nuclei, but we will also monitor secular changes in the comets activity, explosive spontaneous outbursts, coma morphology, and dust trails that constrain comets' mass loss. TESS' sampling cadence, 27-day pointing duration, and instrumental stability promises a dataset of unprecedented quality. We expect to produce an extensive and uniform survey that can dramatically improve our understanding of cometary behavior and evolution.

G022153 Targets

Debris disks serve as laboratories for studying planet formation, and their presence is expected to correlate with that of planets. YSO disks, by contrast, are the building blocks for planets that eventually form. We propose 2-minute cadence photometric monitoring of a sample of 161 M and K dwarfs with circumstellar disks to search for star/disk interactions, characterize stellar var-iability of disk hosts, and potentially identify transiting planets. The stellar rotation and flare data will help constrain system characteristics (e.g. age, inclination angle), and can be used to test the hypothesis that flares can shape debris disks.

G022155 Targets

Around 1 in 5 solar-type stars hosts a debris disk, a multi-component structure comprised of optically thin dust and planetesimals of 1-100 kilometers in size. The evolution of debris disk incidence and properties contains information about the migration of distant giant planets, the rate of giant impacts, and the late stages of terrestrial planet formation. However, debris disks evolve over timescales comparable to stellar lifetimes, and evolution studies are thus hindered by the difficulties of age-dating field stars. Gyrochronology provides the most robust and efficient means of age-dating large numbers of FGK stars. We propose to measure rotation periods and ages for tens of thousands of solar-type dwarfs detected with WISE and test various models of debris disk evolution.

G022156 Targets

Stellar models incorrectly predict M dwarf radii and effective temperatures by several-to-tens of percent. Existing model-independent M dwarf measurements of sufficient precision are few and largely restricted to short-period M+M binaries, where interactions can be significant. However, we can now measure model-independent parameters for M dwarfs eclipsing higher-mass stars (spectral types B-G) greatly expanding the sample. We propose for TESS 2-minute cadence observations of 105 EBs with at least one M dwarf component to precisely measure the primary and secondary eclipses. The 2-minute cadence is necessary for resolving the ingress and egress shapes to the requisite precision to measure ingress/egress durations and hence masses and radii below 5%.

G022157 Targets

Polaris, the current North Pole Star, is the brightest Cepheid in the sky, and features a dominant pulsation period of approximately 3.974 days. As the prototypical Classical Cepheid, the star has served as a laboratory for studies of the period-luminosity relationship, stellar pulsation, and massive star evolution for more than a century. Ironically, despite this concentrated study - and over 750 ADS publications - much remains uncertain about this valuable astrophysical laboratory, including its mass, radius, age, and evolutionary state. TESS provides a unique and crucial opportunity to clarify this confusing situation and to test the stability of Polaris' light amplitude as well as the presence of additional short-timescale variability previously reported for the star.

G022158 Targets

What happens to the planetary systems after the red giant (RG) expansion is largely unknown. Theory predicts a gap in the distribution of orbital periods, due to the opposite effects of stellar mass loss (planets pushed outwards) and tidal interactions (planets pushed inwards). Hot subdwarfs (HSDs) are peculiar stars that lost almost all their envelope near the tip of the RGB. The envelope ejection may be related to common envelope (CE) evolution and indeed 50% of these stars are in post-CE close binaries. The other half HSDs may have experienced the same CE ejection by a fainter companion (massive planet or BD), that may or may not have survived the RG phase. In order to heavily test this hypothesis we propose to observe 1192 apparently single HSDs with Tmag<=16 searching for transits.

G022161 Targets

The occurrence rate of planets as a function of planetary mass and orbital period, and of stellar mass, provides powerful constraints upon models of planet formation, migration, and evolution. Kepler has provided such measurements for FGKM stars, but the short-period planetary population of more massive stars is largely unexplored. We propose to use TESS to observe a sample of A-type main sequence stars in order to find hot Neptunes around these stars. This will provide the first measurement of the occurrence rate of small planets around intermediate-mass stars, increasing our knowledge of planet formation and migration around these stars. It will also provide an excellent sample of planets for studying the impact of high-energy radiation upon planetary atmospheric escape.

G022163 Targets

We propose to create and release image differences and variable-source light curves from TESS FFIs for multiple time-domain communities. We will build image models and image differences from an upgrade of our data-driven model for under-sampled, crowded imaging (the CPM; developed for Kepler and K2). In addition, we will extend the CPM for individual-source light curves by incorporating time-domain photometric data from the ZTF or external users; this stabilizes CPM on long time scales for time-variable sources in the TESS-ZTF overlap. We will deliver (1) image predictions and difference images in FFI image formats, interoperable with all TESS community tools, (2) calibrated TESS light curves for sources with ZTF alerts, and (3) open API for users with other kinds of external data.

G022164 Targets

We propose to conduct the most comprehensive study of variability in very-low mass stars and brown dwarfs, enabled by the TESS mission s long-term continuous photometric monitoring, red sensitive passband and broad sky coverage. We will examine the light-curves of nearly a thousand spectroscopically verified ultracool dwarfs to characterize brightness modulations, measure rotation periods and determine flare rates, including a sample of two min cadence targets to study flare profiles and short duration variability. This study will fundamentally probe the nature of the atmospheric, structural, and rotational changes at the end of the stellar main sequence, and how these physical processes manifest as broadband variability through magnetic activity and weather.

G022165 Targets

K2 observations revealed that a significant fraction (>10%) of local field M dwarfs are fast-rotator stars, with periods < 4days. Many of these stars may constitute the long sought-after population of young, low-mass stars in the vicinity of the Sun. Most of them also show evidence of significant flaring activity in the long-cadence K2 light curves. In TESS cycle-1, we used a selection algorithm to identify these potential flaring M dwarfs based on distance, proper motion, and UV-emission; early results show a very high (>60%) success rate in identifying fast-rotating/flaring M dwarfs. In cycle 2, we identify 2,565 of these active field M dwarfs are already target as CTL objects; we propose to add an additional set of 689 nearby active M-dwarfs to achieve a magnitude limited (G<15) sample.

G022166 Targets

Planet Hunters (PH) has proven successful at crowd sourcing visual inspection of Kepler light curves to detect long-period (P > 600 days) exoplanets that would be invisible to traditional automated search pipelines. Now that PH classification of all Kepler M-dwarf light curves has been completed, we seek 2-minute cadence TESS observations of 4110 of these targets and 58 other known long-period exoplanet hosts in the Kepler field, to combine with FFI photometry in light curves to be injected into the PH interface. With a specialized pipeline that includes an injection/recovery study, we will 1) identify new long-period candidates, 2) refine properties of previously reported candidates in the sample, and 3) constrain the occurrence rates of long-period exoplanets around M-dwarfs.

G022169 Targets

We propose the characterization of outbursts in northern Be stars. Classical Be stars are rapid rotators of spectral type B and luminosity class V-III which have an equatorially concentrated circumstellar disk. The disk is fed by discrete mass loss events called outbursts. Rapid rotation alone cannot explain the ejection episodes, and non-radial pulsations (NRP) have been proposed as an explanation. We propose to verify the correlation between the NRP regime and the feeding of the envelope by combining ground-based spectroscopy data with the identification of outbursts and the measurement of small changes in pulsation frequencies with TESS 2-min cadence observations. Fourier analysis of photometric data will be performed using a methodology developed by our group for CoRoT and K2 Be stars.

G022171 Targets

Essential to understanding the history of the Galaxy's stellar populations, ages are among the most difficult to measure properties of stars. Accurate ages provide leverage on problems ranging from exoplanet habitability to the Galaxy's chemical evolution and age. Gyrochronology, an empirical relation between rotation and age, is believed to be among the best current methods of stellar age determination. We propose to test several competing gyrochronology models using wide binaries in the TESS fields. Such pairs can help unravel and quantify the rotation-activity-metallicity vs. age relations for main sequence stars. They span a much broader range in age and metallicity than stellar clusters, which often have mixed populations and have lost low mass stars.

G022172 Targets

Be stars are near-critically rotating non-radially pulsating B-type stars that episodically eject mass and form orbiting viscous 'decretion' disks. As such, they are valuable astrophysical laboratories for a variety of processes. Be stars show diverse behavior with widely ranging timescales and magnitudes, necessitating a statistical study of the class. They are bright and relatively common, but tend to lie near the Galactic plane and have largely been avoided by space photometry. TESS thus provides an excellent and rare opportunity to study Be stars, and in particular their pulsational properties which may hold the key as to what drives the enigmatic Be phenomenon. We will obtain spectra and polarization measurements simultaneous with the TESS observations of selected targets.

G022173 Targets

Active binary stars are cool stars characterized by strong chromospheric, transition region, and coronal radiation. Photometrically, the stars are variable primarily due to the presence of starspots and flares. The higher activity levels seen in these active binaries make these stars a natural laboratory for the study of magnetic activity. TESS offers us the opportunity to undertake systematic study of issues such as differential rotation, spot evolution, and flare rates for 37 such systems, supplemented by ground-based photometry from the Evryscope program.

G022176 Targets

We propose TESS observations of a sample of cool helium-rich white dwarf stars to search for rotational photometric modulations associated with the presence of magnetic spots. Examples of this are seen in hydrogen-rich white dwarfs. Finding clear examples of this in cool He-rich white dwarfs would help to clarify the true frequency of magnetism in white dwarfs and help explain the distinct deficit of binary systems among white dwarfs, by strengthening the link between white dwarf magnetism and common envelope mergers.

G022177 Targets

Pulsating variable stars (PVs) in the instability strip are critical tools in Galactic structure studies and modern cosmology, representing key transition states in stellar evolution. Yet the masses and radii, fundamental quantities in comparing PVs with theory, are difficult to infer directly from observations. We propose to use TESS full-frame images to discover delta Scuti, RR Lyrae, and Cepheids in eclipsing systems. Eclipses, lasting >hours, with depths of order >0.5 1% are expected in binary systems with >days orbital periods. Discovery of an eclipsing RR Lyrae would be a first and new eclipsing delta Scuti and Cepheids would add to the precious few known. We will release catalogs of TESS PVs and undertake phased-resolved spectroscopic followup to determine mass and radii.

G022179 Targets

Massive stars, while few in number, play an outsized role in the evolution of the universe through their roles in chemical enrichment and as Type II supernova progenitors. Accordingly, models of their stellar structure and evolution are fundamental to our understanding of astrophysical topics as diverse as star formation, stellar winds, and the evolution of the interstellar medium. Improvement of the models can only come through confrontation with observations, and high-precision asteroseismology constitutes the ideal observation set. In this project, we plan to perform asteroseismology of 8 B stars, primarily SPB and Beta Cep stars. Our list is unique in that all of our targets have previously been observed using high precision photometry from space with the WIRE satellite.

G022182 Targets

There are ~100 known planets around M dwarfs, but only one system around an ultra-cool (>M7) dwarf: Trappist-1. Ultra-cool dwarfs are arguably the most promising hosts for atmospheric and biosignature detection in transiting planets because of the enhanced feature contrast in transit and eclipse spectroscopy. We seek to continue a Cycle 1 TESS survey to monitor 13 of the brightest ultra-cool dwarfs over 27.4 days. To maximize the probability of detecting transiting planets, we have selected only targets seen close to equator-on. Spin-orbit alignment expectations dictate that the planetary systems around these ultra-cool dwarfs should also be oriented nearly edge-on. Any planet detections in our pilot survey will immediately become top priority targets for JWST transit spectroscopy.

G022183 Targets

Gamma-ray bursts (GRBs) are the brightest electromagnetic events known to occur in the universe, and are characterized by brief flashes of gamma ray energy concentrated from 0.1 to 1 MeV.The commonly-accepted basic model for GRBs involves the gravitational collapse of a massive star to form an accreting compact object, beginning from an initial event such as the collapse of a massive star, in the case of long GRBs, or the coalescence of two compact objects (neutron stars) for short GRBs. In this proposal, we plan to use the TESS fields to search for visible progenitors to GRBs detected during and immediately following TESS Cycle 2, taking advantage of the large field of view and systematic observing pattern of TESS in an attempt to find such progenitors directly.

G022184 Targets

We propose to exploit the remarkable photometric accuracy and evenly sampled TESS two-minute light curves to improve our physical insights on the mechanism driving the coherent, superorbital modulation in the wind-fed Supergiant X-ray Binary 2S 0114+650. We will search for optical signatures of the ~2.7 hr neutron star rotation period, which may indicate X-ray reprocessing in the donor star, and to investigate donor star variability the first uninterrupted high S/N optical light curve. With the short-cadence TESS light curves, spanning two 11.7 day binary orbits and the maximum and minimum of the 30.7 day superorbital modulation, our TESS observations of 2S 0114+650 are the next logical step towards characterizing the interaction between the slowly spinning neutron star and B1 Ia star.

G022187 Targets

State of the art radial-velocity (RV) exoplanet searches are currently limited by RV signals arising from stellar magnetic activity: while Earth mass planets orbiting Sun-like stars induce a sub-m/s reflex signal, processes such as acoustic oscillations, magnetoconvection, and large-scale magnetic structures produce signal in excess of 10 m/s. These activity processes have characteristic timescales ranging for minutes to month, and must be fully characterized for the successful discovery of low-mass exoplanets. We propose simultaneous TESS and HARPS-N observations of 41 carefully chosen, low-activity stars in characterize the effects of stellar activity on nearby Sun-like stars. The range of stellar timescales requires a long measurement baseline (several rotation periods) with a high ob.

G022192 Targets

We propose to identify transient dimming or dips among TESS lightcurves of stars observed in Cycle 2. Dips are thought to be caused by circumstellar dust; among T Tauri-like stars they are a probe of inner disk conditions and, around older stars, a signpost of exocomets. Most dipper stars have been identified by eye or metrics of periodicity and asymmetry of the lightcurve. We propose an automated analysis of FFI lightcurves, combining statistical calculations with a novel anomaly detection that separates normal variability from short-duration anomalies, including dips, followed by a deep learning approach to distinguish astrophysical signals from systematics based on co-trends between stars, allowing us to describe more diverse and rare events around a wider range of stars.

G022195 Targets

The large consistent data sets provided by space based photometric survey missions such as Kepler or TESS give the unique opportunity to combine the signal of many planets to search for more subtle effects, that can not be detected in individual systems alone. For Kepler we already demonstrated the technique of adding lightcurves of many sub-saturn sized planets for a robust detection of their secondary eclipses. Here we propose to extend this method also to TESS data.

G022197 Targets

TESS high quality light curves show not only the transit but the entire orbital phase curve, including the 2nd eclipse and sinusoidal phase modulations. Those modulations are shaped by the star-planet gravitational interaction and by atmospheric processes in the planet s atmosphere, hence they contain a large amount of information. We have recently completed a study of the WASP-18b TESS phase curve. Here we propose to expand that work to a systematic study of phase curves of short period transiting systems containing a massive planet. This will push to the limit TESS s scientific potential by extracting all information encoded in the light curves, leading to characterization of a sample of massive planet atmospheres and studying star-planet tidal interaction.

G022198 Targets

We propose to explore the full landscape of cool dwarf planet occurrence by expanding the planet detection pipeline and occurrence rate machinery we developed for our successful Cycle 1 proposal and incorporating a sophisticated new TOI vetting framework. We will improve the ability of our pipeline to detect both single transit events and ultra-short period planets (USPs) and probe the frequency of these planets in cool dwarf planetary systems. We will also measure cool dwarf rotation rates and ages and investigate how rotation varies with age and stellar mass, which will help constrain stellar activity, system stability, atmospheric escape, and planet habitability. Finally, we will investigate the planet-metallicity correlation for low-mass stars to probe the extremes of planet formation.

G022199 Targets

We propose to build a comprehensive suite of tools to extract light curves from TESS FFIs, remove co-moving trends, categorized them with a machine learning algorithm, and fit promising binary candidates with MCMC algorithms. We estimate that the resulting catalog will contain over 100,000 binary stars with well-measured orbital parameters. With a population such as this, there are many important topics that can be addressed, including tidal deformations, ellipsoidal variations, and eccentric binary evolution. For binary systems with late-type main sequence stars and orbital periods on the order of 10 days, the photometric variability due to these mechanisms will be roughly 100-1000 ppm, a sweet spot easily accessible with TESS for millions of FFI sources brighter than T ~ 12 magnitude.

G022200 Targets

Recent data from Kepler mission revolutionized the exoplanetary science not only by providing exoplanet demography, but with discovery of starspots and superflares on diverse planet hosting stars. This opens up a new question on how these transient sources of ionizing radiation affect exoplanetary environments in the form of atmospheric erosion and atmospheric chemistry. Here we propose to extend our current project to observe and characterize young solar analogs to space weather environments of K type stars of various ages. This will be done with TESS 2-min cadence observations of a carefully selected sample of Late G to late K dwarfs and to focus on a single question with fundamental importance to search for life: What is the level of stellar activity in young and mature K stars and ho.

G022201 Targets

This proposal seeks to capitalize on the consistency, high precision photometry, instrument stability and high temporal cadence exposures uniquely afforded by TESS observations to collect 30-minute full-frame images of a sample of gamma-ray detected Narrow-line Seyfert 1 galaxies (NLSy1s) and blazars in the continuous viewing zone in pursuit of two main goals: 1) Determine the presence of statistically significant similarities in the variability profiles of NLSy1s and blazars and determine if that variability is more likely due to accretion or orientation. Use this stable, high fidelity data as a training set to identify blazars and \nlsy\ by their variability in other TESS fields

G022203 Targets

Stellar noise is the greatest factor limiting the RV detection of low-mass planets. Here we propose to make high-cadence, high-precision RV observations of 93 nearby FGK stars simultaneous with TESS observations between July 2019 and June 2020. We will use the TOU spectrograph (demonstrated <1m/s), to which the PI has full, dedicated access. These long-baseline, simultaneous time-series will be a unique and unprecedented dataset for us to develop and refine methods to model the stellar RV signals that currently hamper planet detection. This data and analysis toolkit---which will be made available publicly---will be crucial to ensure that continuing improvements of RV instruments result in confirmation of the smallest TESS planets and detections of lower-mass planets than current limit.

G022204 Targets

We propose to obtain 2-minute light curves with TESS for a sample of known long-period EBs, sourced from the Kepler, Catalina, and ASAS-SN surveys, to measure stellar rotation periods and search for eclipse timing variations. These known long-period EBs represent a rare and valuable population of systems, which TESS is uniquely positioned to enhance our knowledge of. High fidelity light curves available from TESS Cycle-1 short-cadence (2-min) data have already shown the ability to recover stellar rotation due to starspot modulations. TESS will provide precise eclipse timing for systems discovered by many previous surveys, in many cases spanning 10-20 year baselines. This sample will be especially valuable for testing ongoing studies of star and planet formation and dynamical evolution.

G022205 Targets

One extremely interesting and relatively unexplored question of exoplanet demographics is that of the occurrence rates of planets around very metal-poor stars ([Fe/H]<−1). TESS provides a large enough sample of these stars for us to place significant observational constraints on competing planet formation theories. In this proposal, we lay out a plan for calculating robust occurrence rates of planets orbiting very metal-poor stars, using a carefully selected sample of TESS targets. In addition to quantifying their exoplanet occurrence rates, we will provide a legacy of high-precision, well-sampled light curves of these stars, which date back to the birth of the Milky Way.

G022207 Targets

TESS s continuous 30 minute cadence provides crucial early time data on explosive transients, probing a window that is inaccessible to traditional ground-based surveys. We propose to identify transients within the TESS sectors with ATLAS and PS1, alert the public, and trigger extensive complementary photometric and spectroscopic observations. Our program will determine the types of companions in SNe Ia progenitors using features in the early LCs; explore the physics of SN using subtle features during their rise; constraint the radius and properties of progenitor stars of core-collapse SNe using their shock break-out; and constraint the light curves of exotic and rare events like superluminous SNe, tidal disruption events, and fast transients.

G022208 Targets

Compact binaries must have undergone dramatic orbital shrinkage, possibly first via the Kozai mechanism and tidal interaction, and then during the common envelope phase. Detecting period variations in eclipsing binaries is key to identifying candidates undergoing these processes. Here we propose for TESS 2-min cadences for ~1100 short-period (<0.5 day) eclipsing binaries identified from WISE. We will combine WISE and TESS light curves to search for period changes over ~10 years of observations, to measure orbital evolution in close binaries, and to discover binaries with decaying periods possibly on their way to the common envelope phase. Measuring orbital changes in this large sample will allow us to probe key stages of binary evolution.

G022209 Targets

We propose to observe pulsating subdwarf B (sdB) stars to determine orbital solutions for possible wide binary and/or substellar companions using the light-time delay in pulsation times, which is called the pulsation timing method. TESS is an ideal instrument to measure pulsation timings of pulsating sdB stars. Plausible sdB formation channels are common-envelope (CE) ejection, stable Roche-lobe overflow (RLOF), and binary white-dwarf merger. Among these, the CE channel results in short period binary systems (P < 10 days) and the RLOF channel results in long period binary systems (P > 500 days). About 150 short-period sdB systems were studied so far. However, not many long-period sdB systems were studied and more samples are needed to constrain the RLOF channel.

G022210 Targets

TESS s continuous 30 minute cadence will provide crucial early time data on explosive transients, probing a window that is inaccessible to traditional ground-based surveys. We propose to identify transients within the TESS sectors with ATLAS and PS1, alert the public, and trigger complementary photometric and spectroscopic follow-up. Our program will determine the types of companions to progenitors of SNe Ia using features in the early LCs; explore the physics of SN using subtle features during their rise; constraint the radius and properties of progenitor stars of core-collapse SNe using the signatures of shock break-out; and constraint the light curves of exotic and rare events like superluminous SNe, tidal disruption events, and fast transients.

G022211 Targets

We propose to complement TESS core science by leveraging NASA s investment in the TESS mission to increase by up to several hundred the yield of long-period planet candidates. We will identify and vet single transit signals likely to have a planetary origin. We will release these candidates to the community in a timely fashion to enable efficient follow-up. This program will provide a large sample of temperate planet candidates transiting bright stars which, if confirmed will be amenable to a variety of follow-up studies. In turn, these studies will place constraints on the composition and formation of long-period exoplanets.

G022214 Targets

Asteroids provide a unique window into the dynamical history of the solar system. Understanding asteroid physical properties, and in particular their rotation rates, allows us to model their collisional history. Accurately measuring long period rotation is crucial to understand the distribution of asteroid rotation rates. Ground based surveys, such as PAN-STARRS and SDSS, are designed for asteroid discovery, and are unable to rigorously identify long period rotation rates. Space-based facilities, such as WISE, do not provide the wide field of view required for an unbiased survey. We propose to leverage TESS s unique capabilities of precise, long-term monitoring across a huge sky-coverage to accurately survey more than 4,000 main belt asteroids, and generate light curves of unprecedented .

G022216 Targets

Young low-mass accreting stars known as classical T Tauri Stars (CTTS) show substantial variability on timescales as long as years. Short cadence light curves from limited K2 and ground-based studies show significant accretion variability on timescales down to a few minutes that remains relatively uncharacterized. To quantify short timescale variability in CTTS, we request 2 minute cadence observations of all of the bright CTTS in the Taurus star-forming region. Our target list consists of 15 CTTS which are the best targets for a study of accretion variability given the wealth of ancillary data. Multiple targets have archival HST UV observations, from which accretion properties have been determined and which will aid in our interpretation of the TESS data.

G022217 Targets

There are about 100-300 million binary White Dwarfs (BWDs) in our Galaxy. About 100 have been found with periods of under about 1 day. BWD with periods under 1 hour have gravitational wave merger times < 100Myr. They are expected to dominate the gravitational wave background for LISA and 11 known BWDs are compact enough to be detected individually by LISA. These systems have complex origins involving mass transfer via stable Roche overflow or unstable common envelope evolution, and various possible fates. Only 7 binary WDs have been found to eclipse. All have short periods, an extremely low mass WD (<0.35Msun) and three have extreme mass ratios of 1:5 that are hard to explain. The 2018 Gaia DR2 makes possible a comprehensive search for short period eclipsing BWD in TESS 2-min data.

G022218 Targets

Warm Jupiters (WJs), giant planets with 10--100 day orbital periods, pose a major challenge to our understanding of how planets form and evolve. We need a larger sample of transiting WJs to test theories for their origins. However, the TESS core program will only discover a handful due to long orbital periods and low occurrence rates. Also, future SC and ground-based observations can yield valuable constraints on WJ properties, but prioritization based on observability and scientific value is needed to choose the best targets. We propose to discover and catalog WJs in full frame images; fit WJ light curves and produce transit ephemerides; and produce a prioritized list of continuous viewing zone WJs as future SC targets and a prioritized catalog of WJs for ground-based follow-up.

G022219 Targets

Our X-ray surveys of a small sample of cool AGB stars with FUV excesses reveal X-ray emission in 40% of our sample. The X-ray emission shows the unexpected presence of magnetically-confined and very hot gas (Tx~35-150 MK), and quasi-periodic variations on hour-long timescales, likely associated with an accretion disk around a main-sequence companion. HST UV observations show flickering on ~minute time-scales for our key fuvAGB object, confirming the presence of an accretion disk. We propose continuation of our successful cycle 1 TESS survey to search for flickering in TESS's optical band for a statistical sample of AGB stars with UV emission. The resulting database of high-cadence, high-sensitivity light curves will provide an unprecedented window into binary interactions in AGB stars.

G022221 Targets

We propose to use TESS 30-minute cadence Full-Frame Images (FFI) to undertake studies of binary systems and active galactic nuclei (AGN) that are impossible to perform using ground-based facilities. The specific topics we will investigate are: (1) stellar binaries, in particular, candidate black hole systems showing ellipsoidal modulation, (2) Eclipsing white dwarfs and subdwarfs, and (3) aperiodic variability of AGN on timescales of 0.02-5 days For these topics, we will exploit the complementarity of TESS and ZTF. To enhance the impact, the same tools and data we develop for our focused science studies will be made available to the wider astronomical community, providing new capabilities for a wide range of time-domain science using TESS. These include simultaneous ZTF/TESS data.

G022222 Targets

We propose a photometric survey of magnetic OBA stars using TESS to detect and characterize three types of variability of these objects: rotational modulation, stochastic variations and pulsations. This will lead to precise rotational period determinations and will help probe magnetospheric structure and surface spots. Detecting pulsations will provide a means to link surface magnetism to the internal structure and better understand surface spindown due to magnetic braking, yielding critical information for stellar evolution models. Given its high precision, rapid cadence and long temporal baseline, TESS provides us with a unique opportunity to detect all three forms of variability, which will prove critical in testing and improving our knowledge of these stars.

G022223 Targets

Hot stars represent a relatively unexplored population of planetary hosts. Bright and nearby hot stars represent ideal hosts for exoplanetary atmosphere characterization given their very different spectral qualities (e.g., a small number of broad, shallow lines) and their low levels of stellar activity. We propose observing a sample of 534 stars with spectral types A9 and hotter with magnitudes brighter than 7.5 Tmag and that reside within 100 parsecs of the Sun. These observations will be able to detect super-Earth planets, provide constraints on planet formation and system architecture for hot stars, and supply ideal, and likely cloud-free planets for atmospheric characterization. As demonstrated in Cycle 1, this sample will also provide observations of stellar oscillations in hot stars.

G022224 Targets

Short-period gas giants present many compelling observational opportunities and theoretical conundra. Their large masses and short periods can facilitate follow-up, particularly of radial velocities, and the distribution of orbital periods provides a sensitive probe of tidal interactions. Unfortunately, among candidate planets discovered by TESS, these planets will be among the most challenging to confirm, but predictions of yields suggest tens of thousands may be found using full-frame images from TESS. A focused transit search involving analysis of phase curves can ameliorate some of these challenges. We propose to use full-frame images from TESS to search for short-period giant planets with a search for transits and out-of-transit photometric variations.

G022227 Targets

TESS will observe over 85% of the sky in Full-Frame Images (FFIs). The overlap of sectors near the ecliptic poles provides ~350 days of coverage in the Continuous Viewing Zone (CVZ). This is a valuable place to search for planets due to the long baseline. Over 100,000 stars on the Candidate Target List in the CVZ will not have 2-min data; some these will host observable transiting exoplanets. We will discover more than 200 planets in the CVZ using FFIs, and swiftly add them to the 2-min target list as ToOs. The new 2-min data, combined with FFIs, will provide a rich dataset to constrain planet and star properties, search for additional planets, and constrain planet masses through transit timing variations. This work provides a major contribution to the yield of the most valuable planets.

G022228 Targets

Recent work has shown that ignoring starspots systematically biases measurements of exoplanet radii. Here we propose a strategy for mitigating starspot-induced exoplanet radius biases, based on a large sample of spotted stars observed in TESS Cycle 2. The approach will deliver constraints on both the typical starspot coverage fraction and the typical starspot temperature contrast, as a function of spectral type and rotation rate. This program will leverage the TESS Cycle 2 overlap with the Kepler prime field and portions of K2 fields.

G022229 Targets

One of Kepler's most exciting breakthroughs was the discovery of circumbinary planets (CBPs). Only about a dozen were found, however, leaving a vast gap in our understanding similar to the state of exoplanet science 20 years ago when only hot Jupiters were known. TESS, and only TESS, will allow us to detect an order of magnitude more CBPs using a new technique we have developed and tested: the occurrence of multiple transits during one conjunction. In addition to enchanting individual-case discoveries and their intriguing dynamics, our sample will enable statistical studies of occurrence rates, formation, and habitability of CBPs (an astonishing ~30% of Kepler CBPs are in the habitable zone), as well as provide a deeper understanding of the formation and evolution of close binary stars.

G022230 Targets

We propose to observe twenty-three cataclysmic variable stars (CVs) during Cycle 2 of TESS at a two-minute cadence. Our target list aims to maximize TESS's contribution to CV research by focusing on types of CVs that are currently underrepresented in both the Kepler and TESS archives. Most of the CVs in our target list have strongly magnetic white dwarfs, and TESS observations of these systems would revolutionize the study of magnetically-controlled accretion much as Kepler did for non-magnetic accretion in CVs. Additionally, several targets will be visible for many sectors and will offer unique insight into instabilities in the mass-transfer rate on long timescales. These targets are highly variable on timescales of minutes, necessitating a two-minute cadence.

G022231 Targets

Widely separated stars that are co-moving and assumed to be co-eval are benchmark systems for testing stellar theories. We have selected a sample of co-moving stars from Gaia DR2, and propose to measure lightcurves and rotation periods of ~2,000 stars. Our sample focuses on co-moving groups with low-mass stars paired with a solar-type star or white dwarf. We will measure ages for the companions, rotation periods for the low-mass star, and derive a robust period-age relation for the most common star, the field M dwarf. We will test our assumption of coevality by examining a subset of "twins" with common kinematics and fundamental properties. The twins will allow us to test the widely held assumption that stars of the same mass and age share the same rotation properties.

G022232 Targets

It is well known that giant planet occurrence is correlated with host star metallicity, and this is thought to support the core accretion model of planet formation. While the core accretion model also suggests that small planets should be less common around stars with [Fe/H] < -0.5, existing observations have not established or rejected the reality of a metallicity effect for small planets. We propose to search for transiting planets around spectroscopically-confirmed FGKM dwarf stars with [Fe/H] < -0.5. We will compare the occurrence of small planets in this metal-poor sample to a control sample of solar-metallicity stars selected in exactly the same way. The proposed observations will conclusively establish or reject the reality of a small planet metallicity effect.

G022233 Targets

We propose to search for eclipses and orbital brightness variations of known hot Jupiters (HJs) in order to study the effects of reflection, thermal emission, ellipsoidal variation, and Doppler beaming on the light curves and in turn probe the planets atmospheric composition, structure, and dynamics. Given TESS s ability to acquire continuous optical observations for a sizable number of HJs, it is an ideal facility to use to enhance exoplanet science done with facilities like HST and Spitzer and to inform atmospheric studies with JWST. In the proposed project, we will ultimately explore atmospheric dynamics and the presence and composition of clouds for a number of HJs and determine if these characteristics are correlated with a particular stellar or planetary property.

G022236 Targets

We propose to create high-precision light curves for ~400 young (1-5 Myr) intermediate mass stars using TESS full frame images at 30-minute cadence. Ground-based observations inform us that young BAF stars are variable due to a combination of accretion (for the Herbig AeBe objects), circumstellar obscuration, and starspots. However, detailed studies of this variability and its relationship to the stellar environment have never been carried out on a large scale. Starting with TESS cycle 1, we are performing the first comprehensive analysis of light curve morphology among young, intermediate-mass stars and its relationship to magnetic activity as well as circumstellar disk properties. The results will be compared to our previous space-based work on low mass K/M stars in young cluster.

G022237 Targets

AM CVns are binaries with 5

G022238 Targets

Planets in binary systems are intrinsically interesting, particularly if the two stars are far enough apart to be spatially resolved. The discovery, confirmation, and characterization of transiting exoplanet in visual binary systems demands a bit of extra work, but these systems can offer unique observational opportunities. They can serve as powerful laboratories for understanding planetary dynamics, evolution, destruction, and atmospheres. Here, we propose to search for planets transiting a sample of comoving visual binaries that were newly identified from Gaia DR2. Using both postage stamps and full frame images, we hope to find new easy-to-observe exoplanet systems and enable new controlled experiments in planetary physics.

G022240 Targets

We propose to investigate a set of 11 low-mass, short period, eclipsing systems containing M dwarf stars using TESS short cadence data. Eight of these systems are eclipsing binaries (EBs) that have had their component masses and radii measured to high precision, while the other three are Kepler triple and quadruple star systems containing at least one M dwarf. We will improve the mass and radius estimates of the EB and multi-star systems which already are among the best measured. For the triple and quadruple star systems, we will also measure the internal structure constants of the M dwarfs, which will allow us to constrain their interior mass distributions for the first time.

G022241 Targets

In this proposal we focus on 55 Cnc e, a quintessential super-Earth in a tight orbit and transiting a nearby star that is visible to the naked eye. We propose this star as 2-minute cadence target in TESS' cycle 2. The 27-day time coverage of this system will enable the characterization of previousy observed phase variations that cannot be explained by scattered light from the planet. This signal may be due to circumstellar gas or dust in the orbit of 55 Cnc e, that could also be associated with the planet. We will also monitor the time variability of these phase variations, and search for a secondary eclipse. In addition, measuring the planet's radius in the unique bandpass of TESS will allow a comparison with transit depths measured at other wavelengths with HST, JWST and CHEOPS.

G022242 Targets

Although TESS was designed to find transiting exoplanets, it will be a powerful tool for extragalactic transient studies. TESS's full-frame images serve as ideal data products for studying active galactic nuclei (AGN) variability. Specifically, \tess's unique high-cadence and high-precision will enable us to more accurately determine if AGN variability is caused by the ``lamp post/reprocessing" model Frank et al. 2002. This analysis, called continuum reverberation mapping, has never been done on a large scale before. We propose to harness TESS's capabilities in tandem with Swift and ASAS-SN to systematically study AGN variability on an expansive platform never before possible.

G022243 Targets

Among the most exciting results from the Kepler Mission were the discovery of the transiting circumbinary planets. While few in number, these "Tatooine" planets captivated the world's imagination. But the circumbinary planets are much more than just curiosities - they have the most accurately measured radii of any exoplanet and they place stringent constraints on planet formation and migration theory. In this proposed research we will use 2-minute cadence TESS data to measure the stellar eclipses times with a precision of ~15 seconds. Using these eclipse times we can refine, or in some cases for the first time, measure the masses of the Kepler circumbinary planet.

G022244 Targets

The transient sky is ripe for TESS. The FFIs will not only be a treasure trove for exoplanet science, but they also present a great opportunity for the transient community. TESS will uniquely produce high-dynamic range, high-cadence FFI light curves for large amplitude, bright transients. We propose to capitalize on the \tess{} FFIs in two ways: 1) At its fastest, TESS data will only be downloaded and made available every two weeks. We will observe the full \tess{} field with an increased cadence (4-6 times per day) using ASAS-SN. We will discover TESS transients first from the ground in real-time to allow extensive multi-wavelength and spectroscopic early-time follow-up observations to complement the exquisite TESS light curves will be made public quickly.

G022245 Targets

TESS offers us a unique opportunity to search for transients in a previously unexplored time domain. The short 2-minute cadence allows us search for transients that evolve on timescales of minutes over 50 square-degrees, whereas the 30 minute cadence allows us to hunt for transients with time scales <1 day over 1000s of square-degrees. We propose to search all TESS pixels, from both the short and long cadence data, in the same way as we have done for Kepler. From this program we will: discover new transients and conduct follow-up observations to understand the events; provide the first rates for extremely rapid transients (<1 day); train a recurrent neural network to detect TESS transients.

G022246 Targets

Metallicity plays a critical role in physical processes in stellar interiors, surfaces, and evolution. Equally important, metallicity also regulates planet formation. However, certain aspects of stellar physics and planet formation have never been tested at extremely low metallicity ([Fe/H]$<$-1). Halo stars---as the first generation of stars in the Milky Way--are metal-poor, providing an excellent low-metallicity laboratory for stellar physics and planet formation. Here, we propose to (1) study a ``golden" sample of halo stars---for which we will have TESS asteroseismology data---to establish an empirical relationship between photometric variability and surface gravity, i.e., a ``flicker" method in the metal-poor regime; (2) embark on a search for transiting planetary systems with the lo.

G022247 Targets

Precise masses and radii, inferred from detailed analysis of eclipsing binary (EB) systems, are a critical part of our understanding of stellar physics and evolution. Recent space-based surveys have enabled precise measurement of masses, radii, and internal structure of giants through asteroseismology. The KELT transit survey has been running for 10+ years. Using its long photometric time baseline, we have identified and begun to characterize several giant-giant eclipsing systems with traditional methods. We request high-cadence TESS photometry for a small set of giant EBs. These data will enable the first direct comparison between the eclipse and seismology methods for giant stars. We expect the results of our analysis to form a new benchmark in the masses and radii of evolved stars.

G022250 Targets

The TESS mission is not currently targeting any significant number of low-mass stars from the local halo population in the 2-minutes cadence mode. We propose to remedy this situation by targeting 1,213 nearby and relatively bright (G<15) low-mass K and M subdwarfs from the local halo. While local halo stars have been targeted in the K2 mission, with no exoplanet detected, there is a chance that the 2-min cadence data might lead to the detection of Neptune or Jupiter sized planets that would otherwise be overlooked in 30-min cadence mode. Light curves will also likely turn up eclipsing binary systems.

G022251 Targets

We propose to extract and analyze TESS light curves for 242 selected candidate transiting planet systems in the Northern ecliptic sky. All our candidates have been identified by the Qatar Exoplanet Survey and have been screened through follow-up spectroscopy. These light curves will be used to confirm and characterize transiting planets, including giant planets around early type stars and subgiants, to look for additional transit signals, and check for transit timing variations. We propose 2 minute cadence observations for 100 targets which are included in the latest version of the CTL catalog but are not among the top priority targets for the TESS team. The remaining 142 targets will be analyzed using the full-frame images.

G022252 Targets

M dwarfs (M < 0.7 M_Sun) are prime targets in the search for Earth-like worlds, yet their high levels of magnetic activity may make them unsuitable habitable planet hosts. Their magnetic activity is driven by rotation and convection, evolves over time, and is manifested in part as frequent, unpredictable, and energetic flares. Via high-energy radiation (X-ray/UV) and energetic particle emission, flares drive exoplanet atmosphere chemistry, erode atmospheres, and impact habitability. We propose to continue and expand a successful TESS M dwarf flare program to provide crucial information on the evolution of flare activity over time, the cumulative energy output from M dwarf flares, and place constraints on which M dwarf planets are most likely to be habitable.

G022253 Targets

M-dwarfs are enticing targets for small transiting planets in the habitable zone. TESS will find hundreds, some bright enough for atmospheric probing by JWST. However, our knowledge of these planets is frustrated by poor constraints on the host M-dwarfs. The EBLM program was created to solve this. Over 400 eclipsing binaries have been found with F/G + M stars, with 10+ years of spectroscopy to unveil masses and metallicities. We now require TESS short cadence lightcurves to obtain primary and secondary eclipses, and hence measure the radius and temperature. Our southern sample was already observed in Cycle 1 (G011278), and with the northern targets, we will produce the most comprehensive sample of M-dwarfs known, and significantly refine the mass-radius-composition-temperature relation.

G022254 Targets

We propose to observe 85 nova-like variables, post-novae and recurrent novae in the "quiescence" following their last nova explosions when bright accretion disks are expected to dominate their light. TESS is needed for its continuous coverage rather than for ultra precision. We will utilize a newly developed, analytic accretion disk model that probes a disk's dimensions, mass, and interior distributions of density and temperature.The observations will deliver the first substantial library of bright disk (non-eruptive) CV light curves to the astronomical community. Eclipsing CVs are of particular interest because they give information on disk morphology.The disk analysis software is ready, tested, and has already been applied to the T Pyx-type recurrent nova CI Aql with good results.

G03007 Targets

Super-Earths and Neptunes in close-in orbits are the most common types of planets around Sun-like stars. The search for planets around young stars is our best proxy to watching planet formation and evolution in action. Stars and planets are continuously been formed in the Solar neighborhood, and yet field young stars are an untapped regime for planet searches. The library of light curves that TESS is building provides an unique opportunity to search for young field stars and the planets they may host. We will search for these planets, estimate their ages, validate and confirm their presence. We will construct a distribution of physical and dynamical properties of small planets as a function of age: an evolution pathway that led to the dominant planet demographic around Sun-like stars.

G03012 Targets

We propose to observe 8 gamma-ray blazars with TESS in a combination of FFI and 2-min cadence data. TESS light curves, along with polarimetric and radio monitoring that we will perform for the sample will allow us to analyze properties of turbulent plasma in jets of blazars that have never been explored previously in this way. This is a continuation of a Cycle 2 program, with the addition of new gamma-ray blazars, which is crucial for sampling their properties across different sub-classes and for theoretical modeling. We will perform a correlation analysis between TESS, FERMI LAT gamma-ray, Swift XRT, and radio light curves, and optical polarization data that will provide with unprecedented accuracy the relative locations of high energy and optical emission regions in the jets of blazars.

G03026 Targets

We propose to investigate three possible physical origins of the optical variability in gamma-ray blazars: jet turbulence, mini-jets in the jet, and changes in the jet Doppler factor. The observable characteristics derived from light curves are lengths and strengths of flares, year-to-year baseline brightness changes, and slopes of power spectral densities. Combinations of characteristics point to specific physical origins. Our targets are the optically brightest gamma-ray blazars in the southern ecliptic hemisphere from our accepted Cycle 1 proposal. We will use 10-min FFI data for 43 targets to measure the power spectral densities and baseline brightness, and we will use 2-min cadence on the 7 brightest targets to measure the lengths and strengths of flares on the shortest timescales.

G03028 Targets

We intend to obtain very high precision light curves of a sample of detached eclipsing and spectroscopic binaries, which we have been monitoring spectroscopically for the last few years within the Comprehensive Research with Echelles on the Most interesting Eclipsing binaries (CREME) project. The light curves will be combined with our precise radial velocity (RV) measurements in order to obtain accurate and precise, absolute stellar parameters. This is a continuation of a successful proposal from C1 and C2.

G03033 Targets

HD 6532 is a well studied member of the class of pulsationally variable stars called the rapidly oscillating Ap (roAp) stars. TESS Cycle 1 observations of HD 6532 revealed a very different pulsation mode geometry than that previously observed from the ground. With simultaneous TESS and ground-based multicolour photometry, we aim to investigate the origin of the observed differences, thus testing the oblique pulsator model, which is used to describe the pulsations in the roAp stars, in a way that has never been attempted before. The results will have the ability to discredit a widely used model, show that the star has changed its pulsation axis, or allow for the 3D modelling of the atmosphere of a star with photometry alone. To achieve our goals, we request the 20-sec cadence mode of TESS.

G03035 Targets

We propose to do an asteroseismic characterization of late-type dwarfs. These stars pulsate very rapidly, and the new 20 second cadence mode of TESS is ideal for observing these stars. There are three science goals of this investigation: (1) To determine the mass, radius and ages of these stars; (2) To examine whether the mass-radius relationship in these lower-mass main-sequence stars is the same those of the earlier-type main-sequence stars; and (3) To extend the age-activity relation to lower masses.

G03041 Targets

We propose a large program (TEQUILA) to analyze TESS FFIs for all NGC+IC galaxies. It will exploit the precision photometry, high-cadence/multi-year baseline, and nearly all-sky coverage of TESS in the search for tenuous nuclear supermassive black hole (SMBH) accretion in the local galaxy population compiled in bright galaxy catalogs (e.g., NGC galaxies). The unique combination of TESS capabilities makes it the ideal facility for identifying and characterizing low-level SMBH accretion in the local universe. Based on TESS-detected nuclear variability from FFIs, TEQUILA will identify SMBHs at the centers of NGC galaxies, quantify the duty cycle of flares in low-rate accretion flows and measure their general variability properties.

G03044 Targets

Pairs of quasi-periodic oscillations (QPOs) in X-ray binaries have been observed and studied for several years at X-ray wavelengths. These QPOs display tight coupling between their frequencies such that the ratio of the QPOs is constant throughout several observed systems. More recently claims of similar QPOs to those observed in X-ray binaries have been claimed in accreting white dwarf systems at optical wavelengths on timescales ranging from 20 seconds to a few hours. However those results have been based on very few QPO cycle counts and limited to ground-based photometry of a handful of systems. We propose TESS 20 second cadence observations of a sample of 74 accreting white dwarfs to search for and characterize QPOs in these systems in order to constrain their elusive physical origin.

G03046 Targets

The evolution of planetary systems after the main sequence is largely unknown and no short period planets around isolated White Dwarfs (WD) have yet been detected. Some show evidence of metal pollution or gas and dust discs indicating that planetesimals and even dwarf planets up to the size of Pluto have strayed too close to the WD have subsequently been tidally disrupted. There is at least one known system where this can actively observed, WD1145+017. Such objects would only survive a star s evolution to a WD at distances greater than at least 1AU implying these objects may have been scattered by unseen planets. We propose to observe all WDs with magnitudes <17.5 with similar evidence of planetary systems to search for further examples of ongoing tidal disruption of planetesimals.

G03051 Targets

We propose to re-observe the active weak-line T-Tauri star CVSO 30 with TESS in Nov. 2020 at 2 min cadence to study the extremely hot, young, and controversial Jupiter candidate CVSO 30 b. A first TESS light curve of the 2.7 Myr old star CVSO 30 shows strong rotational modulation with periodic (0.45 d), transit-like flux dips superimposed on it. An additional very cold jupiter in the system suggests that a recent planet scattering event may have given rise to its current architecture. Combined with ground-based results, the TESS data are consistent with a decline in period of the hot Jupiter, potentially caused by inspiraling. The proposed re-observation is a unique opportunity to study the transit depth and timing, which are indispensable to better understand the system.

G03052 Targets

TESS has observed an order of magnitude more low mass stars in short cadence mode than Kepler. This has allowed us to determine the energy and rate of flares in a large sample finding that, surprisingly, flares do not appear preferentially when the dominant starspot is close to face-on. It has also allowed us to identify more than 200 low mass single stars with rotation periods shorter than 1 day. Contrary to expectations, many of these do not show evidence for flare activity. Here we bid to observe all low mass stars which were observed in Cycle 1 in short cadence to be observed again in Cycle 3. This will enable us to answer questions such as how the flare rate and energy and spot coverage varies over a timescale of months to several years.

G03053 Targets

TESS has observed thousands of solar-type stars during its initial 2-year mission. Returning to sectors and observing these stars again will open doors into the study of magnetic variability and allow for the search of stellar cycles much like the Sun. In this proposal, we would like to return to observe solar-type stars from Cycle 1 which were a part of our initial study to investigate if the stars exhibit any changing magnetic behaviour.

G03054 Targets

We propose to determine the ages of stars in Nyx, a recently discovered Galactic stream. There are two science questions that will be addressed in our study: (1) What are the ages of stars in the stream? (2) Is there a spread of ages among the stars? In answering these questions, we will be characterizing what may be the oldest subset of accreted stars near the Solar position.

G03059 Targets

Massive stars are important metal factories in the Universe and progenitors of core-collapse supernovae. However, a major shortcoming of stellar evolution models is their large uncertainties for interior rotation and convective core overshooting. This is because we lack detailed observational constraints on massive star interiors. Fortunately, most massive stars pulsate in gravity and pressure modes, which are extremely sensitive to a star's interior physics. The TESS mission is providing the first long-term and high-precision photometric data set for a large sample of massive stars. In this project, asteroseismology applied to 2-min TESS light curves will allow us to mitigate these large uncertainties currently in stellar evolution theory.

G03060 Targets

Metallic-line A (Am) stars show abundance anomalies produced by diffusive settling and radiative levitation which should reduce the He abundance in the pulsation driving region and inhibit pulsations. Nevertheless, many Am stars show gamma Dor, delta Sct, and higher frequency roAp-star like modes, and some also show magnetic activity. Neither the pulsation driving mechanisms, nor the origin of the magnetic fields or abundance anomalies are well understood. This proposal is a follow-on to our TESS Cycle 2 proposal, for which 2-min cadence data is being taken on Am stars having detailed spectroscopic abundance determinations. For Cycle 3, we propose to extend observations to 49 additional chemically-peculiar stars to provide a definitive set of constraints to address these problems.

G03061 Targets

We propose to observe 73 Cepheids during TESS Cycle 3 in 2-min cadence. The prototype delta Cep shows phased brightenings in X-ray from Chandra and XMM data According to Engle et al. (2017), "If additional Cepheids are confirmed to show phased X-ray variations, then delta Cep will be the prototype of a new class of pulsation-induced X-ray variables." Our objective is to determine whether Cepheids show transient, possibly phased, brightenings in their optical light curves, which would motivate X-ray observations. 2-min cadence is needed to time-resolve the rise of a brightening event, and to increase S/N to detect a low-amplitude event. 2-min cadence is also needed to reveal features in Cepheid light curves caused by turbulence, etc., that will inform envelope and atmosphere models.

G03063 Targets

The atmospheres of planets evolve under the influence of their parent star. For planets orbiting within the habitable zone of low-mass stars, these effects can be magnified due to their proximity to the host star. We propose TESS two-minute light curves of the targets that will be observed by the NASA-funded Star-Planet Research CubeSat (SPARCS) to resolve the short-lived flares (typical lifetimes of a few hours), quantify the optical stellar rotational variability, and determine the flare-frequency distribution. There are 7 SPARCS target stars that will be observed by TESS in Cycle 2. The TESS and SPARCS data will provide multi-wavelength flare frequency distributions, rotational modulation, and total flare energies that will enable new scaling laws between the optical and UV.

G03064 Targets

We propose to produce, and make public, light curves for all ~100,000 known star cluster members brighter than T = 16 observed in the TESS full-frame images during Cycle 3. The light curves will be generated using an image subtraction photometry procedure which we have adapted to TESS and are currently applying to Cycle 1 and 2 observations through GI support. We will search the light curves for transiting planets, expecting to triple the number of transiting planets known in clusters. This will shed light on the timescales for processes in planet formation, evolution, and migration. The public data set will also be a gold mine for stellar astrophysics, including studies of gyrochronology, variability and tests of stellar evolution.

G03068 Targets

Exomoons remain persistently evasive to modern astronomy. Their detection holds much promise regarding how planetary systems form and evolve. Recently, we discovered a novel means of identifying exomoons using transit timing variations (TTVs) that is applicable to TESS data. Orbital stability demands that moons will be sufficiently short period that their associated TTV signal will always be above the Nyquist frequency (undersampled). Our new work shows that exomoons appear as longer period TTV aliases, piling up close to the Nyquist frequency, unlike planet-planet TTV signals that are preferentially longer period. We identify 63 Southern TOIs capable of hosting potentially detectable moons using TESS, which we will analyze with this approach to identify exomoon candidates for follow-up.

G03071 Targets

Accretion is responsible for the growth and evolution of most objects in the Universe, yet many unanswered questions remain in accretion disk physics. We propose to observe a sample of 321 accreting compact objects (comprising a mix of accreting white dwarfs, neutron stars, and stellar-mass black holes) at 2-minute cadence with TESS. This is a continuation of Cycle 1 & 2 proposals to probe into the long- and short-timescale accretion-induce variability for many object types, allowing for both studies on individual objects and ensemble analysis to compare accretion variability across different accretor types. We will also co-ordinate X-ray observations to be simultaneously performed on some targets, allowing us to study X-ray/optical time-lags on week timescales.

G03074 Targets

There are very few stars for which the results of asteroseismology can be compared to independently measured masses and/or radii. Among the list of well-studied stars in eclipsing binary systems we found only one system (AI Phe) for which asteroseismology of the subgiant component is feasible using TESS data (periods peak near 1440s). Only TESS is capable of providing these data. This star was observed during Cycle01, we did not detect oscillations. We would like to reobserve this star in order to combine Cycle01 and Cycle03 data and improve the detection probability.

G03080 Targets

The technique of transmission spectroscopy --- the wavelength-dependent change in the planetary radii due to opacity sources in its atmosphere --- has been one of the main workhorses of the field of exoplanet atmospheres in terms of providing constraints on the atmospheric elemental abundances in gas giant exoplanets. To date, this technique relies on one simple, key assumption: the terminator region we observe during transit is homogeneous. In this work, we aim to test this assumption, proposing to detect signatures of terminator inhomogeneities using the most precise transit lightcurves to be obtained by the TESS mission during its extended mission.

G03091 Targets

Massive stars play an outsized role in the evolution of the universe and models of their structure and evolution are fundamental to our understanding of astrophysical topics as diverse as star formation, stellar winds, and the evolution of the interstellar medium. Improvement of the models can only come through confrontation with observations, and high-precision asteroseismology constitutes the ideal observation set. This project is a continuation of a Cycle 1 program to re-observe targets originally observed from space for asteroseismology using the WIRE satellite two decades ago. We request additional observations because we find that the frequency resolution from only one year of TESS data is marginal for uniquely identifying pulsation mode frequencies required for asteroseismology.

G03092 Targets

Transiting warm giant exoplanets (Rp>4RE, T<1000 K, P>10 days) are fundamental objects to study, as they are ideal laboratories for tests on planet formation and evolution. Their detection and characterization, however, is very challenging due to their longer periods (which makes them hard to detect from ground-based transit surveys), making TESS the ideal mission to detect &characterize them. In this proposal, we aim at detecting new warm giant exoplanets in TESS' extended mission, which we will couple with radial-velocity measurements to characterize the masses and architectures of these exciting systems. This will allow us to put strong constraints on the theories of giant planet formation, and provide to the community exciting new systems to characterize with HST and the upcoming JWST.

G03095 Targets

Evolved massive stars are observed in a broad menagerie of physical states, all of which are variable on timescales from minutes to decades. Studying their interiors, surfaces, and winds provides powerful constraints on their evolution. We propose to construct a legacy archive of homogeneous, high precision light curves of Galactic evolved massive stars, while simultaneously collecting continuous observations of hundreds of stars in the Magellanic Clouds. These observations will allow us to explore recently-discovered pulsations and stochastic variability across the upper HR diagram. Our proposed observations are well within the capabilities of TESS, allowing us to gather an unprecedented sample of light curves that will inform massive star research for years to come.

G03096 Targets

With space asteroseismology we can measure the internal rotation of evolved stars. Subgiant stars are especially valuable because we can also measure their surface rotation, which is difficult or impossible for more evolved stars. Prior studies have given us strong evidence for cores rotating faster than their surfaces, but only for small subgiant samples. We request observations of 310 high-priority subgiant stars in the southern continuous viewing zone. A one year time series will yield high quality data capable of measuring internal rotation, and we have arranged complementary ground-based data to fully characterize these important targets. This powerful sample will permit tests of gyrochronology and stellar angular momentum evolution theory, and it has other broad applications.

G03102 Targets

Accurate ages provide essential constraints on questions ranging from exoplanet habitability to the Galaxy's chemical evolution. Gyrochronology, an empirical relation between rotation and age, is potentially one of the best ways to determine stellar ages. We propose to test several competing gyrochronology models using wide stellar binaries in the TESS Cycle 3 fields. Such noninteracting coeval pairs can help unravel degeneracies in the rotation-activity-metallicity vs. age relations for main sequence stars. Moreover, they span a much broader range in age and metallicity than stellar clusters, which often have mixed populations and have lost low mass stars. The project will also compare flaring rates from the TESS data and chromospheric activity using LAMOST spectra.

G03106 Targets

Exoplanet characterization is a critical component of current exoplanetary science. In particular, characterization of known exoplanetary systems enables studies of planetary structure and atmospheres, system architectures, orbital dynamics, and the refinement of exoplanet host star properties. This proposal continues our highly successful Cycle 1 & 2 programs and aims to ensure that all known southern hemisphere exoplanet host stars are included in the TESS Cycle 3 target list. The three main science goals of the observations are: (a) observations of potential transits and phase variations, (b) refined transit ephemerides enabling spectroscopic follow-up with future space-based facilities, and (c) detailed stellar properties through astroseismology modeling.

G03107 Targets

Prior to the era of regular space-based photometry, oscillations in solar-like stars were detectable only through heroic radial-velocity efforts from the ground or, in a handful of cases, from earlier space missions such as WIRE, MOST, and CoRoT. In contrast, Kepler allowed us to determine fundamental asteroseismic parameters for hundreds of main sequence stars as well as thousands of red giants. However, despite these successes, a gap remains at the bottom of the main sequence in the asteroseismic HR diagram. Here we propose to attempt to fill that gap using TESS 20-s cadence data. TESS is ideally suited to photometric detection of M dwarf oscillations due to its unique combination of red sensitivity and short observing cadence.

G03112 Targets

I propose a program to obtain 2-minute cadence observations of stars associated with 3 open clusters within the TESS Cycle 3 field of view; Blanco 1, ASCC 19 and NGC 1662. The proposed observations will be vital in studying how the maximum energies and average occurrence rates of stellar flares of K and M stars change with age. These results will help constrain the high-energy environments of young stars, the evolution of their magnetic dynamos and the effects flares may have on the formation and evolution of young exoplanets.

G03118 Targets

Blazars are active galactic nuclei exhibiting extreme variability on different time scales, down to minutes. Their emission is dominated by non-thermal radiation from a relativistic jet pointing toward us, with consequent Doppler beaming. We propose 2 min cadence observations of a small sample of optically and gamma-ray bright blazars to investigate their variability on the shortest accessible time scales. We will analyse TESS light curves with time series methods to infer the most plausible scenarios for blazar variability in general, and microvariability in particular. Multiband photometric and polarimetric supporting observations by the WEBT Collaboration and other ground-based facilities, and space high-energy observations by Fermi and Swift will maximize the scientific return.

G03119 Targets

The addition of a 20-second cadence option to TESS opens up a new window into stellar variability. We know from studies of our own Sun that flares, oscillations, and convection can cause variations on timescales of seconds. However, the variation of other classes of stars at small amplitude and fast cadence are relatively unconstrained. We therefore propose to establish a library of 20 second cadence observations of bright, spectroscopically characterized stars across the HR diagram. This has the potential to identify new sources of variability at lower amplitude and shorter period than ever before. In addition, such well sampled light curves will offer opportunities to optimize the cadence of future surveys and to determine the timescales on which stars can be considered to be stable.

G03120 Targets

The first generation of stars and planets must be deprived of metals. Such a metal-poor environment poses challenges for planet formation, especially at short orbital distances where formation through core accretion dominates. Halo stars can serve as a test ground for planet formation at low metallicity. By searching for planets around halo stars, we will address questions regarding planet formation in extremely metal-poor environments ([Fe/H]$<$-1): when and under what circumstances do the first planets form, and what are their chemical composition and internal structure? We propose a program that involves both searching for planets using TESS data and interpreting the results with modeling and follow-up observations.

G03124 Targets

We propose a mix of 20-second- and 2-min-cadence observations of more than 1800 known or candidate white dwarfs visible in Cycle 3 of the TESS mission. A main objective is to search these white dwarfs for transits of remnant planetary systems with at least 2-min-cadence observations; transits of Earth-sized white dwarfs are likely to be very deep but also very short, just a few minutes, requiring high-speed observations. Our proposed 20-second observations will also enable asteroseismology of a large sample of known and high-likelihood pulsating white dwarfs, continuing the space-based revolution into the interiors of pulsating white dwarfs.

G03126 Targets

Kepler showed that the transiting exoplanet population is strongly sculpted by atmospheric escape. The best observational probe of escape is transit spectroscopy with H I Lyman alpha. However, neutral hydrogen in the ISM completely attenuates the core of the line even for the closest stars, hiding the key bound region of a planet's exosphere. High radial velocity stars offer a solution, as transit signals will be Doppler shifted out of the ISM's 100\% attenuation zone. We propose to search for large, short-period planets around 402 nearby, bright, high radial velocity stars to find planet candidates that will be suitable for Lyman alpha transmission spectroscopy with the HST. We expect to find ~10 planets, which will likely become benchmark systems for directly probing atmospheric escape.

G03127 Targets

Thermonuclear bursts on the surfaces of neutron stars are excellent probes of nuclear physics. Understanding the relationship between the burst recurrence times and the accretion rates onto the neutron stars has traditionally been challenging for X-ray telescopes because the satellites best suited to measure the bursts are in low Earth orbit, with occulations on timescales comparable to the burst recurrence timescales. The X-ray bursts are accompanied by optical bursts from reprocesing in the outer accretion disks, and with the 20-second cadence capability on TESS, it is finally possible to detect the bursts for a large sample of neutron stars. Here we propose to measure the burst recurrence rates using 20-second cadence data on 15 accreting neutron stars.

G03129 Targets

We propose 2-minute cadence observations of 137 low mass stars visible in Cycle 3 and identified as hosting transiting objects in TESS Cycle 1 Full Frame Image data. Our primary objective is to obtain precise radii for the transiting companions in order to study the population statistics for giant planets orbiting low mass stars. Due to the large planet-to-star radius ratios of these systems, the planets are often observed in grazing or near-grazing orbits. In order to precisely measure the radius of the transiting object, we therefore need a robust measurement of the impact parameter. Due to the short transit durations of our targets, we require 2-minute cadence observations in order to achieve a sufficiently high temporal sampling of the in-transit data.

G03130 Targets

Planets are not born in their final state; their orbital and physical properties change as they interact with other planets and their greater environment. Young planets offer a window into these processes as well as a direct probe of the formation and evolution of planetary systems. However, the known sample of young transiting planets remains small, missing the smallest planets (proto-Earths) as well as those in the critical 50-150 Myr range. We propose an expanded search for young planets using Cycle 3 TESS data. Unlike earlier surveys, here we focus on the trove of marginal and unconfirmed detections from our Cycle 1 search, where additional TESS data is critical to distinguish stellar from planetary signals.

G03131 Targets

HD 101065 is a chemically peculiar star with a strong, global, magnetic field making it a member of the Ap star group. Rapid oscillations were found in HD 101065 by Kurtz (1978), making it the first of the rapidly oscillating Ap (roAp) stars. Extensive ground-based studies have unveiled a rich p-mode pulsation spectrum, however, to date, theoretical models cannot account for the observed oscillations. In this proposal, we request 20-sec TESS data of HD 101065 which will supersede every photometric study of this star. These observations will enable us to fully characterise the pulsation spectrum in a way that was impossible from the ground. These data will provide a key step towards constraining non-adiabatic pulsation models of Ap stars as a whole.

G03132 Targets

TIC 350146296 was discovered to be a member of the rare class of rapidly oscillating Ap stars through TESS observations. To date, it exhibits the highest pulsation frequencies of any of the roAp stars. These are above the theoretical limit expected in roAp stars, making this star a key for constraining non-adiabatic pulsation models of Ap stars. However, amplitudes in the current TESS data are suppressed by as much as 27%, caused by apodization, thus hampering the detection of further, low-amplitude modes that are required for a full asteroseismic model. We propose to observe TIC 350146296 in the newly available 20-sec cadence mode for the duration of cycle 3 as this star is in the CVZ. This is a prime example of how the shortest cadence observations will maximise TESS science results.

G03135 Targets

The properties of higher mass stars affects much of astrophysics: from the evolutoin of galaxies to the fate of planetary systems to the formation of compact objects. However, the theory of stellar structure and evolution for intermediate- and high-mass stars has major shortcomings, evident even on the main sequence. Resolving these issues requires confronting theoretical predictions with precise measurements of atmospheric and pulsational properties. To complement TESS's high quality light curve data, we propose measuring effective temperature, gravity, metallicity, vsini, and radial velocities for tens of thousands of stars with convective cores and radiative envelopes (M > 1.2 Msun) using the APOGEE high-resolution H-band spectrograph as part of the SDSS-V all-sky survey.

G03141 Targets

In order to piece together how the planetary evolution process occurs, we need to make detailed studies of the few young planets that are accessible to in-depth follow- up. We propose to make 2 min cadence observations of confirmed and candidate young planets identified in Cycle 1 in order to improve our knowledge of secure detections and confirm the most promising candidate signals.

G03143 Targets

We propose to obtain 2~min cadence observations of MML~48, a young eclipsing binary in a gravitationally bound triple system. The third star appears to be causing variations to both the epoch of the eclipses and the orbital period of the close binary system. Combining the requested observations with photometric and spectroscopic data from 2006 to the present will allow us not only to measure precisely the fundamental properties of the eclipsing stars, but importantly to directly observe the effects of 3-body interactions on the orbital properties of a close binary at a young age. Characterizing the orbits of the stars in such a young system, provides early constraints on the observed distribution of multiple systems giving insight into the formation mechanisms of close stellar binaries.

G03144 Targets

TESS is an extremely powerful facility for studying a broad range of astrophysical objects. During Cycle 2, the Zwicky Transient Facility (ZTF) has been making nightly observations of the current TESS sector in g- and r-band in order to provide a multi-color, high-spatial resolution context for TESS FFI and 2-minute cadence observations. We have made all data from ZTF coverage of TESS sectors public, with nightly release of alert data on transient and variable objects as well as prompt release of light-curves of all ZTF-detectable objects within a TESS sector. In this proposal, we request funding to continue our program of observations of TESS fields during Cycle 3, enhance the legacy value of public ZTF data acquired in Cycle 2, as well as deliver Cycle 2&3 data to NExScI and MAST.

G03147 Targets

Before TESS data became available, the field of asteroseismology was revolutionized by the high precision photometric time series obtained by the space missions MOST, CoRoT and Kepler. The main focus was lying on main sequence (MS) and post-MS stars, but first promising results were also achieved for the pre-MS stages. For a successful application of pre-MS asteroseismology we require the observational detection, resolution and identification of individual pulsation modes, and accurate theories of stellar structure and evolution. For many pre-MS delta Scuti stars, TESS is now the first space mission delivering high-quality, uninterrupted photometric time series which allows to tackle some of the open questions of early stellar evolution theory.

G03151 Targets

Stars undergo dramatic changes as they evolve into red giants, providing a unique opportunity to study the response of exoplanets to changing irradiation, tides and mass loss in a manner that is not possible on the main sequence. We propose to use TESS full-frame images to detect and characterize giant planets transiting red giant stars. Our program combines transits, asteroseismology and radial velocities to address key questions such as (i) the occurrence of giant planets as a function of stellar mass, metallicity and evolutionary state and (ii) the mechanism(s) responsible for the inflation of hot Jupiters. We propose to continue the first near-all-sky survey that combines asteroseismology and transit photometry to precisely characterize exoplanets orbiting evolved stars.

G03154 Targets

The discovery of fast-evolving transients (FETs) has challenged our understanding of extragalactic time-domain astrophysics. However, ground-based transient surveys are inefficient at finding FETs due to their longer cadences. We propose to utilize TESS full-frame images to discover and analyze FETs with a galaxy-targeted search. Given current rate estimates, our search will discover 10-40 FETs during Cycle 3, increasing the sample of high-cadence FET light curves by an order of magnitude. We will make our light curves immediately available for public use and followup.

G03156 Targets

The most powerful tests of stellar structure and evolution come from the brightest stars in the night sky, for which complementary observational techniques (such as astrometry, asteroseismology, and interferometry) can be combined. So far, naked-eye stars (V<6) have rarely been observed with high-precision, high-cadence photometry from space telescopes such as Kepler/K2 due to the large number of pixels required to capture the saturated pixel columns. The key goal of this program is to adapt the novel technique of 'halo photometry' which our team has pioneered with K2 and TESS to perform photometry of extremely bright stars, and obtain high-precision 2-minute cadence light curves of all naked-eye stars, and 20-sec for several targets of special interest.

G03164 Targets

We request support to analyze and model FFI and short cadence data for all exceptionally dusty main sequence stars observable by TESS in Cycle 3. Large amounts of dust seen in the inner planetary systems around these stars is indicative of transient collisional events between massive, rocky bodies. We believe TESS-detected stochastic variability and eclipses in the optical lightcurves of two systems are caused by dust orbiting the star ejected by a large-scale collisional event. Identification of more such systems and analyzing their lightcurves would enable robust mapping of the distribution and evolution of ejecta from large-scale collisional events thus providing critical input to models and theories describing rocky planet formation and evolution processes.

G03165 Targets

We propose to probe the formation history and orbital evolution of seven giant planets orbiting high-mass stars using TESS photometry. Specifically, we will constrain the planets' current-day orbit geometries by measuring the planets' orbital tilts relative to their host stars' rotation planes (i.e., their true spin-orbit angles). Our findings will contribute toward understanding the mechanisms responsible for causing spin-orbit misalignment. This project will be carried out over six months, measuring the true spin-orbit angles of seven planets in the southern sky that will be observed (or re-observed) during Cycle 3.

G03166 Targets

The main scientific aim of this proposal is to obtain the first statistically significant sample of black holes (BH) in detached binary systems. Discovering and characterizing these systems is crucial for constraining binary evolution models and core-collapse supernova mechanisms. We have selected a sample of 2573 objects enriched in BHs that exhibit large RV variations in LAMOST, SDSS, and Gaia data. We would like to use their TESS light curves to search for low-amplitude periodic photometric variations due to ellipsoidal modulation, relativistic beaming, and self-lensing. By combining the currently available radial velocity data and TESS photometry we will be able to create a large sample of BH candidates in non-interacting binary systems, which we will follow up to confirm their nature.

G03169 Targets

RR Lyrae and Cepheid stars play an important role in astrophysics as standard candles, and population tracers. Photometric space missions revealed several new phenomena in them, but were limited by sample size. We propose to observe 211 bright RR Lyrae and Cepheid variables in the southern sky with TESS, to exploit the benefits of the 2-minute sampling. We will investigate the short, shockwave-induced bumps and humps in the light curves, and the structure of the low-amplitude, high-order harmonic peaks in the frequency spectra. We will quantify the amount of period jitter and other cycle-to-cycle instabilities. This way we will test features that are important constraints for the non-linear stellar pulsation models, and may not be fully reproduced in them yet.

G03171 Targets

TESS has great potential as a stellar rotation mission, especially with the extended light curves provided by cycle 3, however detrending methods that preserve stellar variability are required to measure rotation periods longer than around 15 days, even in the continuous viewing zones. We propose to develop methods for detrending TESS light curves that preserve stellar variability and allow rotation periods up to at least 50 days to be measured. We will use these methods to produce a catalog of stellar rotation periods, ranging from 0.1 to ~60 days, for all bright TESS stars in the South.

G03172 Targets

We propose a two-cycle (Cycles 3 and 4), ``all-sky'' survey of the outer solar system using TESS full frame images (FFIs). We will use ``digital tracking'' techniques to efficiently ``shift-and-stack'' FFIs and thus detect moving objects as faint as I~22, well below the single-exposure limit. This shift-and-stack survey using FFI data will discover hundreds of bright Kuiper Belt Objects, Scattered-Disk Objects and Centaurs, and could discover/constrain Planet-9. The newly discovered objects will: (i) be easy to follow-up for physical characterization; (ii) provide a unique all-sky characterization of the size- and spatial-distribution of outer solar-system objects; and (iii) provide insights into rare populations well away from the ecliptic.

G03174 Targets

Superflares (energies 10-1000X the largest solar flares) are often emitted by active M-dwarfs, raising questions about planetary habitability. Few superflares have been observed in multiple colors and at high enough cadence to resolve impulsive (10 s) flare emission. Observations are needed to characterize the flare processes in the stellar atmosphere and determine the effects of superflares on the atmospheres of rocky planets. We propose the largest survey of M-dwarf superflares, cataloguing their rapid emission profiles and temperatures with TESS 20 s cadence and simultaneous ground-based observations. 100 events will occur in Cycle 3 within the TESS FoV simultaneously to Evryscope observations, a 10X improvement in the number of superflares.

G03178 Targets

We propose TESS observations of a select set of cool DC (He-rich) and DQ (trace C) white dwarfs. The objective is to detect coherent photometric modulations due to white dwarf rotation. Such variations have been observed in hotter DA (H-rich) white dwarfs, where frozen-in magnetic spots produce azimuthal photospheric asymmetries. Due to the low temperatures and the lack of spectroscopic hydrogen, magnetic fields are hard to detect in DQ and DC stars. Detections of coherent modulations in DQ or DC stars would be strong evidence for the existence of magnetic fields. There is strong observational and theoretical evidence that white dwarf magnetic fields are the signature of binary merger events which would help account for the well-established lack of white dwarfs in binary systems.

G03180 Targets

AM CVns are binaries with 5

G03181 Targets

The formation of hot Jupiters can be constrained by the existence of closely-orbiting small companions to hot Jupiters. We have already conducted a small-scale search for these companions in the available Cycle 1 TESS 2-minute cadence data, finding 10 possible new planets, but not every known hot Jupiter system was observed at this cadence. We propose to observe the remaining Southern Ecliptic Hemisphere hot Jupiter systems with TESS's 2-minute cadence in a search for small nearby companions that could help constrain the formation mechanism of hot Jupiter systems. This would generate the first complete and uniform survey of hot Jupiter systems down to the precision of TESS, allowing for more detailed population analysis of this mysterious class of planets.

G03182 Targets

We request 20sec cadence observations with TESS for a carefully curated sample of cool stars that our team considers to be the best-characterized in terms of rotation and activity indicators. The aim is to derive asteroseismic properties for this sample, to enable the best-possible comparison between the seismic and rotational evolutionary states of the stars, including ideally, ages.

G03183 Targets

Recently, a system of three small planets were discovered orbiting the early M-dwarf, TOI-700. The two inner planets, TOI-700 b and c, are sub-Neptune in size (1.04 and 2.65 Earth radii) and orbit with periods of 9.98 and 16.05 days. However, the third planet in the system, TOI-700 d, is only 20% larger than the Earth and orbits within the conservative habitable zone of its star with a period of 37.5 day. With extensive characterization observations in progress or being planned, we want to improve our understanding of the TOI-700 architecture and study any short duration flaring activity that could significantly impact the potential for habitability and would have been missed in the 2-minute cycle 1 observations. Therefore, we propose for 20-second cadence observations of TOI-700 to discov

G03185 Targets

We propose to use TESS 2-min cadence data to investigate M-dwarfs of interest from the Next Generation Transit Survey (NGTS) that show short duration transits/eclipses. These include confirmed planets transiting M-dwarfs, m-dwarf/white dwarf systems, and MM eclipsing binaries. All targets show short timescale events that necessitate 2-minute cadence rather than the 10-minute cadence from the FFIs.

G03186 Targets

Be stars are near-critically rotating non-radially pulsating B-type stars that episodically eject mass and form orbiting viscous 'decretion' disks. As such, they are valuable astrophysical laboratories for a variety of processes. Be stars show diverse behavior with widely ranging timescales and magnitudes, necessitating a statistical study of the class. They are bright and relatively common, but tend to lie near the Galactic plane and have largely been avoided by space photometry. TESS thus provides an excellent and rare opportunity to study Be stars, and in particular their pulsational properties which may hold the key as to what drives the enigmatic Be phenomenon. We will obtain spectra and polarization measurements simultaneous with the TESS observations of selected targets.

G03188 Targets

We propose to complement TESS core science by adding several hundred new long-period planets and planet candidates. We will search for and vet single transit planet candidate (STPC) signals in Cycle 3 for targets for which we found STPCs in Cycle 1. We will also identify new STPCs in Cycle 3, and develop a parallel pipeline optimized for identifying STPCs around M dwarfs. These candidates will be released to the community in a timely fashion to allow efficient follow-up. As added value, our program will allow us to update the occurence rates of long-period giant exoplanets. This program will provide a large sample of temperate planet candidates transiting bright stars amenable to follow-up studies, enabling constraints on the composition and formation of long-period exoplanets.

G03195 Targets

One of Kepler's most exciting breakthroughs was the discovery of circumbinary planets (CBPs). Only about a dozen were found, however, leaving a vast gap in our understanding -- similar to the state of exoplanet science 20 years ago when only hot Jupiters were known. TESS, and only TESS, will allow us to detect an order of magnitude more CBPs using a new technique we have developed and tested: the occurrence of multiple transits during one conjunction. In addition to enchanting individual-case discoveries and their intriguing dynamics, our sample will enable statistical studies of occurrence rates, formation, and habitability of CBPs (an astonishing ~30% of Kepler CBPs are in the habitable zone), as well as provide a deeper understanding of the formation and evolution of close binary stars.

G03196 Targets

TESS recently uncovered TOI-270 (TIC 259377017), a remarkable multi-planet system with a super-Earth and two temperate sub-Neptunes transiting a bright M3.5V dwarf with orbits near mean-motion resonance (5:3 and 2:1). Here, we propose for 20 s cadence in Cycle 3 to precisely measure the planets' transit timing variations (TTVs) for planet mass determinations and dynamical studies. Cycle 3 will add 18 new transits of planet b, 10 of c, and 6 of d. The 20 s data will improve TESS' transit timing precision from 2-3 min to <1 min, substantially contributing to our ongoing TTV monitoring campaign. Precise TTVs and masses are pivotal for atmospheric characterization, as TOI-270 provides an unique opportunity to compare atmospheres of multiple planets formed from the same protoplanetary nebula.

G03201 Targets

Ultra-hot Jupiters (UHJs) present opportunities and conundra. Their large masses and short periods facilitate follow-up, particularly of radial velocities. Observational evidence points to ongoing tidal decay of their orbits, demanding accurate ephemerides, and hot Jupiter phase curves evince highly dynamic meteorology. Unfortunately, among TESS candidates, these are among the most challenging to confirm since many false positive scenarios can mimic their signals, but focused light curve analyses and radial velocity measurements can surmount these difficulties. We propose to use Cycles-1 through -3 TESS data plus ground-based observations to confirm UHJ candidates. We will also search for out-of-transit photometric variations to reveal meteorology and masses.

G03202 Targets

We propose to use TESS 20-second cadence data to study flares on 976 low mass stars which are known to exhibit flares during TESS Cycle 1. This is the first time a large and systematic study of the flares on low mass stars will be performed using higher cadence data. We will use this data to i) study flare frequency distributions (FFDs) for a wider range of flare energies than previously observed by the Kepler and TESS missions, ii) examine if FFDs of some flaring stars follow broken power laws, iii) study variation of flare rates as a function of spectral types and ages, iv) develop flare model based on more precise rise and decay time scales, and v) develop flare analysis software 'xoflare' which will make flare studies more convenient in future.

G03204 Targets

Our Cycle 3 TESS GI proposal is to observe and analyze a sample of 31 bright, non-Blazhko, first-overtone (RRc), RR Lyrae variables with the 2-minute cadence program. Our goal is to investigate temporal variability in the primary radial pulsation mode, fo, and the well known non-radial pulsation mode, fx, found in most RRc stars (fo/fx ~ 0.61). For stars with the fx mode, we will also explore variability in any identifiable half-integer, sub-harmonic frequencies. Our ultimate goal is to compare the short-term and long-term variability in order to constrain the period-shifting effect seen in many RRc stars. We will also use the subset of our sample which has published kinematic observations to help constrain the physical properties that produce this non-radial mode.

G03205 Targets

The first year of the TESS all-sky survey discovered a large number of flaring Solartype star targets (~25,734) in the Southern Hemisphere; especially the discovery of TIC43472154, a star that produced ~200 superflares in a year. It is imperative to obtain a large sample of flaring solar-type stars with the TESS 20-sec cadence along with low mass stars for comparison studies in constraining the processes of solar and stellar flares governing magnetic reconnection. Stellar atmospheres contain a plethora of waves such as QPPs and acoustic oscillations. The occurrence of oscillatory waves and pulsations associated with flares puts additional constraints on the interpretation and understanding of the fundamental processes operating in both solar and stellar flares.

G03206 Targets

We propose the observations of 41 southern symbiotic stars selected from the New Online Database of Symbiotic Variables with a 2-minute cadence mode of TESS during the Cycle 3. Such data provide the unique opportunity to reveal and study the low-amplitude short-term variability of symbiotic stars on the time scales of minutes at unprecedented levels and could be a valuable input to the models the inner regions of symbiotic systems and disks studying physical conditions in them.

G03207 Targets

Many white dwarfs have been found to have their surfaces "polluted" by remnant rocky bodies from their progenitors' planetary systems. These polluted white dwarfs are our best observational probe of exoplanet interior chemical compositions, which they can reveal with exquisite sensitivity. However, without a good understanding of the origins of white dwarf pollution, it is impossible to fully leverage the information about chemical compositions from the pollution on their surfaces. Using TESS we will study the origins and process of white dwarf pollution by identifying transiting disintegrating minor planets on their way to polluting white dwarfs. This will help to properly interpret the information about planetary compositions from the surfaces of white dwarfs.

G03209 Targets

We propose to continue the search for and characterization of discrete mass-loss events (outbursts) in southern Be stars initiated in Cycle 1. Rapid rotation alone cannot explain the ejection episodes, and non-radial pulsations (NRP) have been proposed as an explanation. Our goal is to verify the correlation between the NRP regime and the feeding of the envelope by combining ground-based spectroscopy data with the identification of outbursts and the measurement of small changes in pulsation frequencies with TESS 2-min cadence observations. Fourier analysis of photometric data will be performed using a methodology developed by our group for CoRoT and K2 Be stars.

G03212 Targets

The KESPRINT planet team proposes to use TESS 2-minute cadence data to search for planets in a sample of 6101 stars with significantly sub-solar metallicity. The goal is to determine the planet-formation history of the various stellar populations of our Milky Way Galaxy. These stars are all selected from large spectroscopic surveys, and thus the sample is extremely well characterized and well understood. We will attempt to conduct an asteroseismic analysis on the brightest of the target stars, in order to refine the stellar parameters. We will search these lightcurves for transiting planets, and will perform follow-up observations and detailed system modeling on promising candidate planets in order to validate and/or confirm the candidates as planets.

G03214 Targets

We propose to use the TESS full-frame images to investigate the rotational dynamics and temporal activity of comets that serendipitously appear in the TESS fields, monitoring as many as 30 comets in Cycle 3 of the TESS survey. Our primary focus is on temporal phenomena, including measuring rotation rates of the nuclei and investigating changes in the rotation over time, as well as tracking secular activity levels and monitoring for explosive spontaneous outbursts. We will also explore the comets' coma morphologies and search for dust trails that would constrain the comets' total mass loss. TESS' sampling cadence, 27-day observation span, and instrumental stability promise to provide a uniform survey that can dramatically improve our understanding of cometary behavior and evolution.

G03216 Targets

M-dwarfs are enticing targets for small transiting planets in the habitable zone. TESS will find hundreds, some bright enough for atmospheric probing by JWST. However, the field is frustrated by poor constraints on the host M-dwarfs. The EBLM program was created to solve this. Through EBLM over 400 eclipsing binaries have been found with F/G + M stars, with 11+ years of spectroscopy to unveil masses and metallicities. We now require TESS short cadence lightcurves to obtain primary and secondary eclipses, and hence measure the radius and temperature. We propose to re-observe our Cycle 1 sample to improve the SNR, and request funding to develop the most comprehensive sample of M-dwarfs known, and significantly refine the mass-radius-composition-temperature relation.

G03219 Targets

This proposal aims at investigating the impact of stellar birth environment on the configuration of emerging planetary systems. We will identify transiting planets in the recently discovered nearby, massive stellar stream, Meingast 1, which formed in a loose configuration about 120 Myr ago. In comparison to young star clusters at similar ages, like the Pleiades, the stream is an ideal laboratory and a new benchmark for statistical investigations on the physical properties of emerging planetary systems arising from distinct birth conditions (clustered vs. non-clustered). We select 460 stream members from the CTL as 2-min cadence targets. The identified transit candidates will be followed up by a suite of observations using ESO instrumentation for subsequent classification.

G03221 Targets

Here we propose both 20s and 2min cadence TESS observations of known binary and pulsating hot subdwarf stars visible in Cycle 3. We have also identified a large number of candidate variable hot subdwarfs from their anomalously high Gaia flux errors and request 2min cadence data to confirm their variability. Collectively, these light curves will help (i) permit detailed asteroseismological analyses for an unprecedented number of pulsating hot subdwarfs; (ii) greatly increase the number of known and solved binaries; (iii) determine the influence substellar objects have on stellar evolution; (iv) constrain the presence of planetary companions through precise timings; and (v) generally improve our capacity to draw a statistically meaningful picture of this enigmatic stage of stellar evolution.

G03223 Targets

We propose a photometric survey of magnetic OBA stars using TESS to detect and characterize three types of variability of these objects: rotational modulation, stochastic variations and pulsations. This will lead to precise rotational period determinations and will help probe magnetospheric structure and surface spots. Detecting pulsations will provide a means to link surface magnetism to the internal structure and better understand surface spindown due to magnetic braking, yielding critical information for stellar evolution models. Given its high precision, rapid cadence and long temporal baseline, TESS provides us with a unique opportunity to detect all three forms of variability, which will prove critical in testing and improving our knowledge of these stars.

G03225 Targets

We propose to compare new measurements using two-minute cadence data of southern hemisphere ultracool dwarf photometric variability with measurements from our initial work on these targets from Cycle 1 of the TESS mission. Revisiting our sample targets after a several year time base line provides a unique opportunity to not only characterize brightness modulations from rotational variability and/or flares in these stars with greater precision, but assess the extent to which these properties can change on several year time scales. This study provides a fundamentally new probe of long-term activity in the lowest-mass stars, and how their atmospheric physics may change going into the substellar regime.

G03226 Targets

M dwarfs (~0.6 to 0.1 solar masses) comprise 75% of stars in the Galaxy and are known to frequently host small planets. They are prime targets in exoplanet searches, especially those focused on finding habitable, Earth-like planets. However, M dwarfs are strongly magnetically active, sending high-energy radiation and ejecting charged particles at their planets during frequent flaring events. With the goal of understanding the space weather environments that M dwarf exoplanets find themselves in, we propose to continue our successful program investigating the age- and mass-based trends seen in stellar magnetic activity, with a focus on evaluating the quantity, magnitude, and often staggering effects of high energy radiation and charged particles impacting exoplanet atmospheres.

G03227 Targets

Activity cycles are the key to understanding the origin of the stellar magnetic dynamo, but are notoriously difficult to constrain for stars without expensive spectroscopic data. Flares offer a new way to reliably probe activity cycles using photometry alone. Using TESS 2-min data for a sample of stars already having legacy activity cycle spectroscopy observations, we will calibrate this flare-cycle connection, and establish benchmark flare rates for these key stars.

G03228 Targets

The physics of flares is still poorly understood. As a subset of this problem, the physics of quasi-periodic pulsations (QPP) on flares is also poorly understood. Dozens of hypotheses for QPP causation have been proposed, but limited observational data means that we are not yet able to test those hypotheses. Many stellar (as opposed to solar) QPP events previously recorded have periods on the order of hours. Recent observations in GALEX and NGTS suggest that QPPs are present in some flares in UV and white light bands at periods of less than a few minutes. This project targets nearby M dwarfs with 20-second cadence to address the question of whether QPPs with periods of a few minutes are common at optical wavelengths across a broad range of flare energies.

G03229 Targets

Eclipsing post-common envelope binaries (HW Vir systems) are highly important for resolving the poorly understood, very short-lived common envelope phase of stellar evolution. We apply for the time-resolved photometry of 18 known or newly discovered southern HW Vir systems in order to obtain light curves covering their complete orbit. A combination of the length of observations and 2-minute cadence mode of the TESS will allow to well sample the eclipses in these systems with a short duration. Obtained data will allow us to obtain the orbital parameters with the precision not achievable by the ground-based observations and will be used in the modeling of the unique reflection effect observed in these systems.

G03232 Targets

TESS light curves show the entire orbital phase curve, including the transit, 2nd eclipse, and sinusoidal phase modulations. Those modulations are shaped by the star-planet gravitational interaction and by atmospheric processes in the planet s atmosphere. Our long term goal is a systematic study of all TESS phase curves of short period systems. Here we propose to expand our study to TESS Year 3. The combined Year 1 + Year 3 data will result in higher quality phase curves, and will allow looking for variations in the phase curve parameters (i.e. weather variability). Our project maximizes TESS s scientific potential by extracting all information encoded in the light curves, leading to characterization of a sample of massive planet atmospheres and studying star-planet tidal interaction.

G03234 Targets

We propose to observe pulsating subdwarf B (sdB) stars to determine orbital solutions for possible wide binary and/or substellar companions using the light-time delay in pulsation times, which is called the pulsation timing method. TESS is an ideal instrument to measure pulsation timings of pulsating sdB stars. Plausible sdB formation channels are common-envelope (CE) ejection, stable Roche-lobe overflow (RLOF), and binary white-dwarf merger. Among these, the CE channel results in short period binary systems (P < 10 days) and the RLOF channel results in long period binary systems (P > 500 days). About 150 short-period sdB systems were studied so far. However, not many long-period sdB systems were studied and more samples are needed to constrain the RLOF channel.

G03240 Targets

Cataclysmic variables provide the cleanest available natural laboratories to investigate the physics of accretion. The timing capabilities and sensitivity of TESS are well matched to the timescales and amplitudes of accretion variability in these sources. The combination provides an opportunity to test and refine the paradigms of stellar accretion with high-precision, uniform data containing no diurnal gaps. We propose a continuation of our multifaceted observational and modeling program that has the potential to measure the spatial structure of model dependent disk parameters. Like the Kepler/K2 mission, the analysis of TESS observations of CVs will significantly impact our understanding of accretion dynamics and the nature of astrophysical viscosity.

G03241 Targets

This program will obtain short cadence data on known pulsating hot white dwarf (GW Vir) stars, and pulsating planetary nebula nuclei (PNNVs). The main science goal is to explore the coherence of the known oscillations. K2 data showed that some of the longer-period modes in GW Vir itself showed evidence of unexpected stochastic behavior, similar to what is seen in long-period modes in cooler white dwarfs. We plan to study this effect in known hot pulsators. The high duty cycle and long duration of TESS light curves, which far exceed what is available from ground-based studies, are needed. While 2 minute integrations will suffice for all targets, some have short periods for which aliasing may be an issue, so 20 second integrations are preferred for those stars.

G03243 Targets

Mass is a fundamental property of stars and is notoriously difficult to measure for red giant (RG) stars. The photometry provided by TESS and Kepler has proven to be a vital resource for measuring accurate RG masses thanks to the scaling relations that connect a star's characteristic oscillation frequencies to its surface gravity and mean density. We are undertaking a spectroscopic study of ~150 RGs to explore the relationship between planet hosting RGs and RGs with unusual properties suggestive of planet engulfment. We request resources to measure asteroseismic masses for the field RGs in our study that are covered by TESS, utilizing full frame images. Having accurate masses will allow us to assess whether our stellar samples are drawn from the same underlying mass population.

G03245 Targets

Although the Kepler spacecraft offered many groundbreaking insights into cataclysmic variable stars (CVs), it observed very few magnetic CVs, which are semi-detached binaries containing a magnetized, accreting white dwarf. These systems show variability at all timescales probed by TESS, and with TESS's excellent all-sky coverage, it will observe far more magnetic CVs than did Kepler. We propose to observe a selection of these systems in order to test theories of magnetic accretion in a way that has not been possible with ground-based photometry. For two of our targets, we further propose that they be observed at the 20-second cadence if it is available.

G03247 Targets

The Search for Exoplanets Around Metal-poor Stars with T(r)ESS (SEAMSTRESS) Survey seeks to answer the question: ``When and how did planet formation begin in the Universe?'' To achieve this, we have conducted a large-scale search for transits of metal-poor stars in TESS light curves and discovered 49 previously unknown planet candidates around host stars in the metallicity range $-$2.28 $<$ [Fe/H] $<$ $-$0.5, eight of which have lower [Fe/H] than any known transiting planet hosts.

G03250 Targets

M dwarfs account for 75% of all stars. The nearest M dwarfs are the most easily studied; moreover, for the coming decade, the only spectroscopically-accessible temperate, terrestrial worlds will be the ones that transit the closest mid-to-late M-dwarfs. Key stellar properties remain uncertain, notably their magnetic activity, rotation periods, and multiplicity. We propose to continue to gather TESS 2-minute cadence observations of the volume-complete sample of mid-to-late M dwarfs within 15 pc. Short cadence is essential to determine the flare morphologies, while continuing observations will reduce the uncertainties on our flare statistics. We will combine the TESS light curves with our ongoing high-res spectroscopic survey to yield a legacy dataset of our closest stellar neighbors.

G03251 Targets

Asteroseismology is one of the most powerful methods to determine fundamental properties of solar-type stars. However, the currently known sample of stars with asteroseismic detections is small, and many of them are too faint to have the independent constraints necessary to constrain poorly understood stellar interior physics such as convection. Here we propose 2-minute and 20-second cadence observations for the TESS Asteroseismic Science Consortium (TASC) that will double the Cycle 1 asteroseismic yield of solar-type stars, allowing us to (i) establish the first catalog of asteroseismic benchmark stars in the southern ecliptic hemisphere, (ii) probe the physics of stellar convection in solar-type stars and (iii) investigate the efficiency of convective mode excitation for hot stars.

G03252 Targets

Delta Scuti and roAp stars are classes of pulsators sharing the same region of the HR diagram. For decades their pulsations were thought to have different origins, but data from TESS revealed an apparent overlap in their pulsation properties questioning our understanding of the excitation mechanisms at work. We propose to: 1) characterize the statistical distributions of the scaled pulsation frequencies in these pulsators, including the determination of the so far unknown high-frequency end of the roAp star phenomena and; 2) establish whether hybrid delta Scuti-roAp stars exist. These results, which will be key to advance our understanding of the origin of the pulsation in this region of the HR diagram, can now be achieved thanks to the survey-nature of TESS and its 20-sec cadence mode.

G03254 Targets

We propose to perform a focused search for the gravitational self-lensing signature using the TESS Cycle 3 data in order to make the first discovery of a detached compact object with a stellar companion based on gravitational self-lensing. Detection and characterization of non-interacting black holes or neutron stars with stellar companions would enable their population studies and testing of binary formation and evolution models. Towards this purpose, we propose a 2-minute target selection towards systems that are likely to have compact companions with detectable self-lensing signatures.

G03255 Targets

Young moving groups are unique laboratories to probe fundamental processes in star and planet formation. However, the ages of moving groups are frequently poorly constrained, with age differences in the literature of up to a factor of two depending on the method used. Here we propose 2-minute cadence observations to perform the first systematic asteroseismic age determination for young moving groups, using a newly discovered class of high-frequency delta Scuti stars with regular frequency spacings. Our program will yield the first systematic asteroseismic age determination of young moving groups, probe the dynamical architectures of young stars through spin-axis inclination measurements, and shed light on the occurrence rate of delta Scuti stars with regular spacings.

G03256 Targets

TESS has opened up the possibility to understand the nature and occurrence rates of rapid extragalactic transients. The TESS Serendipitous Transient Search (TESTS) builds upon the K2: Background survey, which has detected many transients serendipidously observed by Kepler, to search for rare Fast Evolving Luminous Transients (FELTs) in TESS data. We predict that 3-24 FELTs will be observed by TESS that are detectable to TESTS. We will provide the most comprehensive volumetric occurrence rate for FELTs by determining the magnitude limit, detection efficiency, and contamination factor for every TESS pixel. With TESTS we will produce a catalogue of all FELTs observed by TESS, establish the best occurrence rates, and the nature of these mysterious transients.

G03263 Targets

We propose to use the NASA Infrared Telescope Facility (IRTF) iSHELL spectrometer to confirm and with the radial velocity (RV) method measure the masses of planets discovered by NASA TESS mission orbiting bright K and M dwarf host stars. We also propose to make (mostly) 2 min cadence observations of confirmed and candidate planets identified in Cycle 1 that we are observing with iSHELL in order to confirm the candidates and to constrain bulk densities to inform the exoplanet mass-radius relation. For AU Mic and its planetary system, we propose a 20 second shared risk cadence to better time-resolve the frequent flares present.

G03264 Targets

We will have observed ~34,000 targets in the Southern Continuous Viewing Zone (SCVZ) with the APOGEE2-South H-band R~22,500 spectrograph by the end of TESS Cycle 3, ~14,500 of which are dwarfs and subgiants. This sample is broad and simply selected, enabling a correspondingly broad set of science cases. We propose to provide a curated catalog of TESS SCVZ stars with high-resolution spectroscopy and detailed stellar characterization: we will provide effective temperatures, detailed chemical abundances, and search for flares, convective granulation, and rotational modulation in all sample dwarfs and subgiants. We will use these observations to infer stellar masses, radii, luminosities, and ages using a combination of spectroscopic, photometric, and rotation-based proxies

G03265 Targets

Eclipsing binaries (EBs) provide benchmark measurements of stellar masses and radii that are the foundation of theoretical stellar astrophysics. Large areas of parameter space remain poorly constrained by observations, however, particularly at low masses and young ages. From the few sources that have been studied in this regime, models have been unable to simultaneously describe their observed properties (M, R, T, L). A thorough test of theoretical models requires a sample of EBs that spans both mass and age. TESS will provide the first dataset capable of finding EBs on this scale. We therefore propose for targeted 2-m cadence observations of 174 EBs discovered by our team that reside in young clusters and moving groups. This analysis will provide a global test of early stellar evolution.

G03267 Targets

We propose to further develop and make available to the community a variant of this CPMmodel incorporating ground based data for easy cross calibration to make predictions andimage difference light-curves for sources inTESSFFIs, and to perform studies of transientand variable sources, especially Fast Rising Luminous Supernovae, tidal disruption events,and galactic compact object transients such as X-ray binaries and Cataclysmic Variables.

G03268 Targets

The most important legacy of TESS may be the discovery of small planets orbiting bright, nearby stars amenable to mass measurements with precise radial velocities and atmospheric characterization with future facilities like JWST and extremely large telescopes. The TESS extended mission promises to bolster this legacy further by finding planets that are smaller and longer-period than those from the prime mission. We have seen that ground-based follow-up is crucial for the identification of false positives and selection of the best targets for our community's most valuable resources. We propose for funding to continue our ground-based observing programs that, in the prime mission, represent a majority of the precise light curves and reconnaissance spectroscopy obtained by the community.

G03271 Targets

We propose a broadband campaign of the Gamma-ray binary PSR B1259-63 with TESS and Swift following the post-periastron passage of its 3.4 yr binary orbit. Consisting of a 48 ms pulsar and an O9.5 Ve star with a circumstellar disk inclined to the orbital plane, B1259 shows double-peaked emission at radio, X-ray and TeV energies as the pulsar crosses the Be disk along with powerful flares at GeV energies that at times exceeds the spin-down power of the pulsar. The GeV flares are delayed by 30 45 days and persist up to 90 days from periastron. Our goal is to probe key physical properties of the termination shock and discriminate the synchrotron or inverse-Compton losses driving the strong GeV flares using a discrete cross-correlation analysis from optical to GeV wavelengths.

G03272 Targets

Of the millions of stars that TESS will observe during Cycle 3 in either FFIs or 2-minute cadence, less than 2% are well suited to radial velocity follow up with the current generation of precision RV instruments. We propose to obtain 2-minute TESS photometry of 34,140 stars in the Southern Ecliptic Hemisphere whose effective temperatures and V- or T-magnitudes make them viable RV candidates. Planets found to orbit these stars will have the best chances of obtaining precision mass measurements. Such measurements will make these planets prime targets for future atmospheric characterization efforts with ground-based facilities such as NIRSPEC and ESPRESSO, and space-based missions including HST, JWST, and ARIEL. Of these stars, 21,425 were not previously observed in 2-minute cadence by TESS.

G03273 Targets

M dwarfs stars are the most abundant stellar type and are known to frequently host small planets. M dwarfs exhibit high levels of activity, subjecting planets to significantly more radiation than we receive from the Sun. Just how much this affects their potential habitability remains unclear. We propose to study five highly active M dwarfs, three of which are known planets hosts, using simultaneous TESS 20-second cadence optical data and Swift's X-ray/ultraviolet observations. The combined data will provide a deeper understanding of M dwarf activity in unprecedented detail, enabling us to identify relations between optical, UV, and X-ray activity for low mass stars that will provide valuable inputs into exoplanet atmosphere and habitability models.

G03274 Targets

Studies of small close-in planets have revealed a gap in their radius distribution whose central radius shifts to smaller sizes with decreasing stellar mass in broad agreement with physical models of the emergence of the radius valley. Thermally driven mass loss and gas-poor formation models can explain the existence of the radius valley but make distinct predictions regarding its central radius versus stellar mass with the model discrepancies being greatest around the lowest mass M dwarfs. We propose to target a uniform sample of mid-to-late M dwarfs in the TESS extended mission to resolve the central radius of the valley. Comparison of these measurements to the valley around Sun-like stars will enable the distinction between competing radius valley emergence models versus stellar mass.

G03276 Targets

The activity of the exoplanet host star impacts the interpretation of the atmosphere of the exoplanet by contaminating the spectrum, this can lead to biases such as detecting artificial molecules. With the launch of the James Webb Space Telescope, we need to understand the activity of the stars in more detail in an attempt to mitigate these biases, as the high quality spectra obtained from the instrument will be extremely influenced by the activity of the host star, this has already been shown to be an issue with the Hubble Space Telescope, an instrument with significantly lower data quality.

G03278 Targets

One of the many exciting results from the Kepler mission was the discovery that multiplanet systems are common. We propose to enrich the sample of multiplanet systems by obtaining 20-sec cadence observations of 915 relatively bright stars known to host one or more planets or planet candidates. The main goals of our proposal are to discover additional planets in these systems by detecting transits and transit timing variations and increase the sample of long-period planets by detecting single transit events and estimating the orbital parameters of planets with uncertain orbital periods.

G03279 Targets

Late-type M dwarf exoplanet systems are ubiquitous and open new doors for detailed atmospheric characterization, but by itself, TESS is less effective for these ultra-cool stars. We thus propose a joint TESS and SPECULOOS effort to observe 277 carefully selected, nearby (<40 pc) M5 to M8 dwarfs with 2 min cadence in Cycle 3. On these targets, we can detect temperate Earth-sized planets at>3 sigma using TESS alone and SPECULOOS will be used to rapidly confirm those candidates, strongly expanding TESS reach and impact to the most interesting targets for atmospheric studies with JWST and the ELTs. We will also develop custom TESS 2 min data products, which we will make publicly available immediately, as a service to the community.

G03280 Targets

Clouds are highly ubiquitous in planetary systems, and their abundance and configuration greatly impacts our ability to constrain their atmospheres. Large east/west temperature gradients in planets with equilibrium temperatures of around 1500K are predicted to lead to the accumulation of asymmetric equatorial clouds, and observations of asymmetric optical phase curves in a handful of planets lend initial evidence in support of this east/west discrepancy. Another, more recently proposed method for detecting these clouds suggests that residuals will appear in the primary transits themselves when fit to light curves that fail to take into account cloud inhomogenieties. We propose to use TESS's 20 second cadence to search for these effects in several hot Jupiters with large atmospheric scale h

G03281 Targets

The local volume around the Sun is a laboratory for studying all aspects of star and planet formation. That statement is especially true regarding co-moving, co-evolving young associations like those visualized in Figure 1. The European Space Agency s Gaia telescope (Lindegren et al. 2018) is revolutionizing our understanding of these groups and TESS is well placed to complement and enhance our knowledge of the evolution of stars and their planets in these young stellar associations. In the TESS Cycle 2 call, our team was awarded funds to begin investigating the age-rotation relation for 29 known moving groups and clusters near the Sun with members that span all spectral types (well into the M dwarfs) and are bright enough for TESS lightcurve analysis. Since the time of the last call for

G03284 Targets

Short-period (< 2 hr) cataclysmic variables (spCVs) play a crucial role in understanding fundamental white dwarf physics, binary evolution, progenitors models of supernovae, and the gravitational wave sky. We propose the first continuous high-cadence population study of 99 bright spCV candidates, including 30 systems that will be viewed for 9+ sectors. The short integration mode (20 s or 2 min) should lead to period recovery for even the tightest binaries in our sample and radial velocity followup will yield masses. Constraining system and component parameters, especially for eclipsing systems, will help uncover new coherent LISA sources.

G04005 Targets

We propose to use the new MAROON-X radial velocity spectrograph on the Gemini-N telescope to perform a uniform survey of transiting planet candidates orbiting M dwarfs that were identified in TESS's prime mission. MAROON-X has demonstrated sub-50 cm/s radial velocity precision on M dwarfs and it has delivered ultra-precise mass and orbit measurements of two nearby rocky planets during its first year of operations. Over the next year we aim to use this world-leading capability to complete the follow-up of a further 14 M dwarf planets. We will measure precise masses and orbits of these planets to determine the bulk compositions and orbital eccentricities of the individual objects, and the overall mass-radius relationship and the mass function for M dwarf planets.

G04006 Targets

The study of flares from stars of all spectral type has been transformed by Kepler and now TESS. In particular the study of flares from low mass stars has become of wide interest since it can give insight to how magnetic fields are generated in fully convective and partially convective low mass stars and how their activity can effect the atmosphere of any orbiting exoplanets. In this programme we aim to identify low mass stars with very short rotation periods; determine the flare energy-rate distributions of all stars in the sample and compare them with those observed in Cycle 2 and identify flares showing quasi periodic pulsations.

G04009 Targets

Cataclysmic Variables are accreting binaries with white dwarf primaries and orbital periods in the range 5 mins to many hours. Theyshow a wide range of observable properties based on their orbital period and strength of the magnetic field of the white dwarf. Many of these systems show outbursts every few weeks, months or years. As mass from the secondary star builds up in the accretion disc, it eventually becomes unstable resulting in an outburst. During super outbursts, the precessing warped disc gives rise to a periodic modulation in the light curve which can be modelled to determine how conditions in the disc evolves over the outburst. TESS has shown superb examples of this behaviour. Here we bid for a small number of key targets in 20 sec cadence and more in 2 min cadence.

G04016 Targets

Young stellar clusters provide benchmarks for investigations into both stellar evolution (calibrating stellar evolution models and empirical age relations), and exoplanetary science (discovering planets with known, young ages). A new young association, Group-X, provides a benchmark at an age that is not currently well-represented in nearby clusters (about 400 Myr). We will use TESS Cycle 4 data to significantly improve on the rotational analysis that can be done using Cycle 2 data. We will determine an age for the cluster using gyrochronology, representing the first in-depth look at this cluster.

G04023 Targets

With thousands of known exoplanets, many as small as the Earth, there is increasing interest in discovering exomoons, whose population would inform planet-satellite formation theory and provide greater context to the uniqueness of our home. Recently, it was shown that the TTVs caused by exomoons should manifest preferentially at short periods, whereas planet-planet interactions rarely do. Even with a few epochs, typical of TESS' short baselines, short-period TTVs are still detectable and thus we propose here to seek such signals. Such signals will be checked for compatibility with the exomoon hypothesis, and all significant TTV systems will be released to the community. We identify 39 Cycle 4 TOIs which could maintain detectable moons with this technique that we seek to investigate here.

G04026 Targets

With TESS data products we seek to comprehensively establish whether planetary systems observed around GKM-type stars are allowable or ruled out for A-type stars. This will require the best lightcurve sensitivity possible for A-type stars to try and mitigate their larger size relative to GKM-type stars. Effectively removing high frequency stellar pulsations commonly seen for A-type stars is essential to broaching this goal. We request support to analyze FFI and short cadence TESS data for a selection of A-type stars observed during Cycle 4. The primary goal of the work proposed herein is to determine if TESS FFI (10 minute) cadences are sufficient to model and remove pulsational variability seen in A-type stars, or if shorter (20 second and/or 2 minute) cadence data are necessary.

G04028 Targets

We propose observations of 46 bright Galactic Cepheids during TESS Cycle 4, with 2-min cadence desired. Our objective is to search for transient, possibly phased, brightenings in the optical light curves, indicative of pulsation-produced shocks. Hydrodynamic modeling has shown that shocks can plausibly explain X-ray brightenings discovered in delta Cep (phased) and beta Dor using Chandra and XMM observations. Shocks have been proposed to drive mass loss in Cepheids that may help explain the Cepheid mass discrepancy. Our second objective is to carry out nonlinear hydrodynamic modeling using MESA RSP for an ensemble of Galactic Cepheids to understand the origin of cycle-to-cycle period and amplitude variations, bumps, and other features that are being discovered in TESS Cepheid light curves.

G04030 Targets

The metallic-line A (Am) stars are main-sequence stars of about two solar masses that show enhancements of Ti and Fe-group elements and underabundances of Ca and Sc. These abundance anomalies indicate atomic diffusion processes operating in the stellar envelope that should deplete helium and turn off pulsations via the helium-ionization kappa mechanism. These stars have shallow envelope convection zones that should not be able to sustain a magnetic dynamo. Nevertheless, many Am stars show pulsations as well as spots and flares. We propose TESS observations to discover pulsators, determine frequencies, and characterize magnetic activity. We also propose asteroseismic modeling of the pulsators to understand the origins of the abundance anomalies, pulsations, and rotational variability.

G04032 Targets

We propose to produce, and make public, light curves for all ~100,000 known star cluster members brighter than T = 16 observed in the TESS full-frame images during Cycle 4. The light curves will be generated using image subtraction photometry, which outperforms aperture photometry in crowded fields. We will search the light curves for transiting planets, expecting to triple the number of transiting planets known in clusters. This will shed light on the timescales for processes in planet formation, evolution, and migration. The public data set will also be a gold mine for stellar astrophysics, including studies of gyrochronology, variability and tests of stellar evolution.

G04033 Targets

The nearest M dwarfs are the most easily studied; moreover, for the coming decade, the only spectroscopically-accessible temperate, terrestrial worlds will be the ones that transit the closest mid-to-late M-dwarfs. Key stellar properties remain uncertain, notably their magnetic activity, rotation periods, and multiplicity. We propose to gather TESS 20-second and 2-minute cadence observations of the volume-complete sample of mid-to-late M dwarfs within 15 pc. Short cadence is essential to determine flare morphologies, rotation periods, and search for transiting planets, while continuing observations will reduce the uncertainties on our flare statistics. We will combine the TESS data with our ongoing high-res spectroscopic survey to yield a legacy dataset of our closest stellar neighbors.

G04034 Targets

TESS is collecting unique high cadence, high precision light curves of dozens of yellow supergiants (YSGs). Recent work has found stochastic low-frequency variability (SLFV) to be ubiquitous in YSGs; this variability may be the first direct probe of YSG interiors. We propose to couple ground-based spectroscopy to new and archival TESS data to determine the mechanism driving YSG SLFV, and construct a complete evolutionary sequence of SLFV from main sequence to core collapse. TESS has also revealed a new class of pulsators that are proposed to be massive stars in a second YSG phase. We will use new TESS data to double the number of known YSG pulsators, and use ground-based spectroscopy to constrain their evolutionary status while determining the geometry of the observed modes.

G04036 Targets

White dwarfs are intriguing targets for the search and characterization of habitable exoplanets. Rocky planets in the habitable zones of white dwarfs should be exceptional targets for follow-up atmospheric characterization, and their existence would have important implications for planetary survival and evolution through the post-main sequence lifetime of the star. However, their short transit durations of only a few minutes necessitate high-speed observations. By observing more than 2500 white dwarfs visible in Cycle 4 of the TESS mission at 20-second cadence, we will be able to identify small planets and remnants of planetary systems around white dwarfs, and substantially improve understanding of white dwarf exoplanet demographics.

G04039 Targets

We propose to use TESS 2-minute light curves, combined with new and flexible stellar flare and starspot analysis methods, to search for transiting exoplanets around active M dwarfs that have previously evaded detection. Although M dwarfs are some of the most important targets for current exoplanet studies, their flare and starspot activity often result in light curves that are too noisy for exoplanet detection pipelines. Using careful flare detection and modeling, along with flexible starspot detrending methods, we will be able to carry out the most complete search for transiting exoplanets around active M dwarfs to date. This search will in turn place strong constraints on the planet occurrence rate and dynamical stability timescales for these important planet hosts.

G04046 Targets

Accretion is responsible for the growth and evolution of most objects in the Universe, yet many unanswered questions remain in accretion disk physics. We propose to observe a sample of 404 accreting compact objects (comprising a mix of accreting white dwarfs, neutron stars, and stellar-mass black holes) at 2-minute cadence with TESS and 50 at 20 second cadence. These observations will provide a long-lasting legacy dataset providing a comprehensive library of the optical timing properties of accretig systems. Some of the science questions to be answered with this dataset include the characterisation of quasi-periodic oscillations in accreting white dwarfs, the search for magnetically gated accretion modes, and the mapping of the accretion disk geometry in eclipsing systems throughout disk i

G04047 Targets

We intend to obtain very high precision light curves of a sample of detached eclipsing and double-lined spectroscopic (SB2) binaries, which have a large number of new and unpublished high-resolution spectra (from our own observations). In total, there are over 380 stars in the programme, 76 of which are available for TESS in Cycle 4. The light curves will be combined with the precise radial velocity (RV) measurements in order to obtain accurate and precise, absolute stellar parameters.

G04048 Targets

We propose to observe 30 gamma-ray blazars with TESS in a combination of FFI, 2-min, and 20-sec cadence data. TESS light curves, along with polarimetric monitoring that we will perform for the sample, will allow us to analyze properties of turbulent plasmas in jets of blazars that have never been explored previously in this way. The observations are crucial for sampling properties of gamma-ray blazars across different sub-classes and for theoretical modeling. We will perform a correlation analysis between TESS, Fermi-LAT gamma-ray, Swift XRT and UVOT light curves, and optical polarization data that will provide with unprecedented accuracy the relative locations of high energy and optical emission regions in the jets of blazars.

G04051 Targets

TESS has observed thousands of Solar-type stars during its initial 2 year mission. Returning to sectors and observing these stars again will open doors into the study of magnetic variability and allow for the search of stellar cycles much like the Sun. In this proposal we request 2 min cadence observations of 703 Solar-type stars which are in the Northern Continuous Viewing Zone and were observed in Cycle 2 in 2 min cadence. We will determine if the stars show variability in activity between Cycle 2 and 4 and search for changing activity levels over rotational cycles.

G04054 Targets

HD 38451 is an enigmatic A type star with a slow, irregular variability. It may have changed color without a strong photometric variability during the 19th century, perhaps caused by ejection of shells. HD 38451 is not known to be chemically peculiar like Am and Ap stars, and it is rotating rapidly unlike Am and Ap stars. Yet it appears to be variable at about 200 cycles per day, similarly to the class of rapidly oscillating Ap (roAp) stars. We propose to take advantage of the fact that HD 38451 will be observed with TESS during Sectors 43-45 and obtain nearly uninterrupted 2-min cadence data, so that we may investigate the oscillation characteristics of HD 38451 and its relationship with roAp stars.

G04056 Targets

The bulk composition of exo-planets is a crucial input in planet formation models, and spectroscopy of white dwarfs accreting planetary debris is the only available method to measure it. However, all studies have so far used an assumption that remains untested: "the metals are uniformly distributed over the stellar surface". Given accretion proceeds via a geometrically thin disk, the validity of this assumption is far from obvious. Exploiting the pulsations in G29-38, the metal distribution can be mapped over the surface. However, the evolution of the location of the pulsations is a necessary step. The exquisite continuous long-term TESS photometry has the potential to reduce the aliases, and only the 20-sec cadence mode can to resolve the shortest pulsations (<2min) in G29-38.

G04057 Targets

The nearby 650 Myr-old Hyades cluster is an important benchmark for establishing the rotational evolution of cool stars, including M dwarfs. We will analyze TESS observations of the cluster's core, halo and tidal tail through Cycle 4 to determine rotation periods of its M dwarfs, and use Gaia and ground-based observations to determine their multiplicity. We will examine the dependence of rotation period on binary separation and mass ratio, and use our single-star rotation sequence to test models of M dwarf rotational evolution and calibrate a gyrochronology. Accurate ages for M dwarfs would allow measurements of their planets to be temporally ordered and would refine the timescale for the early phase of elevated X-ray/UV emission and flaring that drives escape of planetary atmospheres.

G04058 Targets

One of the most exciting exoplanet breakthroughs of the past decade was the discovery of circumbinary planets (CBPs). Only about a dozen were found, however, leaving a vast gap in our understanding -- similar to the state of exoplanet science 20 years ago when only a handful of hot Jupiters were known. TESS, and only TESS, will allow us to detect of an order of magnitude more CBPs using a technique recently developed and successfully applied: the occurrence of multiple transits during one conjunction. In addition to enchanting individual-case discoveries and their intriguing dynamics, our sample will enable statistical studies of occurrence rates, formation, and habitability of CBPs, as well as provide a deeper understanding of the formation and evolution of close binary stars.

G04059 Targets

As Doppler spectrometers approach ever higher precision, stellar activity is becoming the most significant challenge when measuring precise masses of exoplanets. Photometry is a valuable tool for mitigating the effects of stellar activity, especially when taken simultaneously with RVs. We propose to observe high-value Kepler targets using the new, ultra-precise Doppler spectrograph NEID, simulatneously with TESS observations. A joint photometry-RV model will be used to mitigate activity in RVs, and provide precise mass estimates for our targets. Models will be run with Kepler photometry, TESS photometry, and both, with a study of the effectiveness of such models being a primary science result. The results of this project will inform future efforts to measure exoplanet masses with RVs.

G04060 Targets

Planets are not born in their final state; their orbital and physical properties change as they interact with other planets and their greater environment. Young planets offer a window into these processes as well as a direct probe of the formation and evolution of planetary systems. However, the known sample of young transiting planets remains small and heavily biased towards larger planets and 400-750 Myr clusters. We propose to use TESS Cycle 4 to identify more of the youngest (5-125 Myr) planets. To this end, we focus on confirming tentative signals identified in earlier data and <50 Myr associations newly identified from Gaia astrometry.

G04067 Targets

Be stars are near-critically rotating non-radially pulsating B-type stars that mechanically eject mass and form orbiting viscous 'decretion' disks. As such, they are valuable astrophysical laboratories for a variety of processes. We are using TESS data to quantify their complex variability, especially in regards to pulsation-driven mass ejection and the dynamics of circumstellar material. A ground-based time-series spectroscopic campaign contemporaneous with TESS observations is being pursued for ~150 Be stars. From spectra, the (changing) density, velocity, and temperature structure of circumstellar matter can be inferred. This information, when combined with TESS photometry, reveals the nature of the physical processes acting in Be stars and their disks upon careful analysis.

G04069 Targets

Ultra-hot Jupiters UHJs present many observational opportunities and theoretical conundra. Their large masses and short periods facilitate follow-up, and observational evidence points to ongoing tidal decay of their orbits, demanding an accurate catalog for long-term monitoring. Their phase curves evince dynamic meteorology involving disassociation, ionization, and magnetic fields. Unfortunately, UHJs are among the most challenging to confirm, but a focused light curve analysis and radial velocity measurements can surmount these difficulties. We propose to use Cycles 1 through 3 TESS data, leavened with ground-based observations and a small number of 2-min cadence observations from Cycle 4, to validate or confirm UHJ candidates and search for phase curves diagnostic of exotic meteorology.

G04074 Targets

Massive stars are important metal factories in the Universe and progenitors of core-collapse supernovae. However, a major shortcoming of stellar evolution models is their large uncertainties for interior rotation and convective core overshooting. This is because we lack detailed observational constraints on massive star interiors. Fortunately, most massive stars pulsate in gravity and pressure modes, which are extremely sensitive to a star s interior physics. The TESS mission is providing the first long-term and high-precision photometric data set for a large sample of massive stars. In this project, asteroseismology applied to 2-min TESS light curves will allow us to mitigate these large uncertainties currently in stellar evolution theory.

G04076 Targets

Stars of spectral type O and B are known as the chemical factories of the Universe and largely guide its chemical evolution. However, major shortcomings prevail in their stellar structure and evolution theory arising from the lack of observationally calibrated internal mixing profiles. Ensemble asteroseismology of early type stars in OB associations recently found by Gaia and observed by the TESS space telescope provides exciting new opportunities to study stellar interiors. Having the precise spectroscopic parameters are crucial for the asteroseismic modeling of these stars, while measurements of the surface abundances provide important constraints on their internal mixing.

G04079 Targets

This program will obtain short cadence data on known pulsating hot white dwarf (GW Vir) stars and pulsating planetary nebula nuclei (PNNVs). The science goal is to explore the coherence of the known oscillations. K2 data showed that some longer-period modes in GW Vir itself showed evidence of unexpected stochastic behavior, similar to that seen in long-period modes in cooler white dwarfs. We plan to study this effect in known hot pulsators to test connections between pulsation and convection. The high duty cycle and long duration of TESS data, which far exceed what is available from ground-based studies, are needed. While 2 minute integrations will suffice for all targets, those with short periods can benefit from 20 second integrations to eliminate aliases.

G04081 Targets

Photometric variability observed in L dwarfs could be due to rotating magnetic spots, clouds, aurorae, or a combination therein. We propose 16 early L dwarf targets for short-cadence TESS observations, 10 of which we will simultaneously observe at infrared wavelengths from the ground. For the 10 targets with simultaneous optical/IR observations, the differences in amplitude and phase between the optical and IR light curves will determine the relative roles of spots, clouds, and aurorae in L dwarf variability. For the remaining 6, we will measure their variability characteristics using TESS data alone. The results are crucial for interpreting future JWST observations of L-type planetary companions to sun-like stars and L-type planetary-mass objects.

G04085 Targets

Stellar flares are short-lived, highly energetic events that have lasting effects on planets in their early developmental stages. Young stars (<5 Myr) are ideal targets to study these processes because they provide a snapshot of earliest stages of star and planet evolution. To date, no flare studies of these stars exist. Only TESS can provide the precision, time-sampling, and continuous coverage needed to characterize flare activity on young stars. We propose to obtain TESS two-minute light curves to resolve short-lived flares in a sample of 225 young stars and to quantify the relationship between flare activity and system properties that have not yet been examined, in addition rounding out results from existing statistical flare studies that do not include the youngest stars.

G04086 Targets

In the hours after explosion, SNe provide clues to how they explode, and what their progenitor star systems were. TESS light curves can pinpoint the moment of explosion and highlight light curve morphologies that may signal shock breakout, companion star/circumstellar interaction, or an unusual nickel distribution. Despite the unique role of TESS, to maximize its science ground-based data must accompany it. Here we will provide discovery data and complete ground-based follow-up of the nearest SNe that will be in TESS Cycle 4 (5-7 SNe total), and will utilize new tools to spectroscopically classify SNe minutes after discovery. This array of follow-up data, including a single HST UV spectroscopic sequence, will help break model degeneracies inherent to the single-band TESS data alone.

G04091 Targets

Here we propose both 20s and 2min cadence TESS observations of known binary and pulsating hot subdwarf stars visible in Cycle 4. We have also identified a large number of candidate variable hot subdwarfs from their anomalously high Gaia flux errors and request 2min cadence data to confirm their variability. Collectively, these light curves will (i) permit detailed asteroseismological analyses for an unprecedented number of pulsating hot subdwarfs; (ii) greatly increase the number of known and solved binaries; (iii) determine the influence substellar objects have on stellar evolution; (iv) estimate the occurrence rate of planets as a function of orbital period and planetary radius; and (v) improve our capacity to draw a statistically meaningful picture of this stage of stellar evolution.

G04096 Targets

TESS light curves show the entire orbital phase curve, including the transit, secondary eclipse, and sinusoidal phase modulations. Those modulations are shaped by star-planet gravitational interaction and by atmospheric processes in the planet s atmosphere. We propose to extend our ongoing long term systematic study of all TESS phase curves to Cycle 4. The combined Cycles 2 + 4 data will result in higher quality phase curves, and will allow to look for variations in phase curve parameters (weather variability). In addition, Cycle 4 ecliptic sectors will provide new phase curves. Our project maximizes TESS s science by extracting all information encoded in the light curves, leading to characterization of a sample of massive planet atmospheres and studying star-planet tidal interaction.

G04098 Targets

Exoplanet characterization is a critical component of current exoplanetary science. In particular, characterization of known exoplanetary systems enables studies of planetary structure and atmospheres, system architectures, orbital dynamics, and the refinement of exoplanet host star properties. This proposal aims to ensure that all known exoplanet host stars within the TESS Cycle 4 fields are included in the target list. The three main science goals of the observations are: (a) observations of potential transits and phase variations, (b) refined transit ephemerides enabling spectroscopic follow-up with future space-based facilities, and (c) detailed stellar properties through astroseismology modeling.

G04100 Targets

We propose for TESS to observe the V1298 Tau system with 2 minute cadence during Cycle 4. V1298 Tau is notable for having four young (23 Myr) planets. The age and estimated low densities of these planets suggest they are in the end stages of formation when planets radiate away formation heat, contract, and lose some atmosphere. These planets are an excellent laboratory for planetary formation and will be a popular target for atmospheric characterization and to understand formation with JWST. 2 minute cadence data from TESS will reduce transit time uncertainties from several hours to tens of minutes during JWST Cycle 1, enabling transit observations with JWST. The TESS data will also constrain possible transit timing variations, placing an upper limit on the mass of these planets.

G04101 Targets

We request 2-minute cadence observations during cycle 4 of 11 exoplanets to probe their light curves for shape distortion due to tides and rotation. These planets' favorable observational properties and the ability of additional observations during cycle 4 may enable, either individually or as a group, key insights into planetary asphericity and interior properties of exoplanets. These observations represent a unique opportunity to, for the first time, obtain the requisite number (>35-50) of transit observations needed to detect asphericity for these exoplanets - that are based upon theory, modeled to possess significant enough asphericity to constrain interior properties.

G04103 Targets

Brightness variations in high-precision light curves encode powerful information about fundamental properties and convective processes in solar-type stars through oscillations and granulation. However, the current sample of stars with detected oscillations and granulation is focused on the Kepler field, and prime mission TESS data do not provide sufficient time coverage to make precise measurements. Here we propose 2-minute cadence observations to measure oscillations and granulation in evolved solar-type stars, which will enable us to (i) probe the efficiency of convective driving and damping of oscillations, (ii) test stellar models by constraining convective properties such as mixing length parameter and (iii) calibrate granulation metrics for TESS stars.

G04104 Targets

Solar analogs - stars with temperatures, radii and metallicities similar to the Sun - play a critical role for stellar astrophysics and exoplanet science. Asteroseismology provides a powerful tool to determine fundamental properties such as mass and age, but due to their small amplitudes and fast timescales oscillations in solar analogs are only available for a handful of stars using space-based photometry. Here we propose to use the unique 20-second cadence capabilities from TESS to establish the first benchmark sample of bright asteroseismic solar analogs, which will enable us to (i) investigate the connection between magnetic activity cycles and stellar age in Sun-like stars and (ii) characterize the radii and eccentricities of small transiting exoplanets.

G04105 Targets

Double eclipsing binaries are systems with two independent but overlapping sets of eclipses. Surprisingly, the population of double eclipsing binaries shows excess near but not exactly at period ratios of 1:1 and 3:2, which is not theoretically understood. Determining the spin state of the individual stars in double eclipsing binaries is the best way to figure out the interplay between tides and dynamical evolution likely responsible for the resonance. We propose to obtain 2-min cadence observations of all known double eclipsing binaries observable in Cycle 4 to determine spin periods of individual components by tracking spots, use the spot eclipses to estimate the obliquity, and search for stellar pulsations.

G04106 Targets

Young moving groups are unique laboratories to probe fundamental processes in star and planet formation. However, the ages of moving groups are frequently poorly constrained, with age differences in the literature of up to a factor of two depending on the method used. Here we propose 2-minute cadence observations to systematically measure asteroseismic ages for young moving groups, using a newly discovered class of high-frequency delta Scuti stars with regular frequency spacings. Our program will yield the first systematic asteroseismic age determination of young moving groups, probe the dynamical architectures of young stars through spin-axis inclination measurements, and shed light on the occurrence rate of delta Scuti stars with regular spacings.

G04107 Targets

We propose to identify background binary false positives via automated pixel-level analysis of postage stamp and/or FFI data. Observed difference images, created by subtracting average in-transit pixels from out-of-transit pixels, will be compared with modeled difference images that assume the transit is on the target or nearby stars accounting for the measured noise in the observed difference image. Bayesian inference will be used to assign a relative likelihood to the star most likely to host the transit event. Identifying these false positives from TESS data will save significant followup cost. Because our method is automated it can be used to create large, uniformly vetted exoplanet catalogs with well characterized reliability.

G04108 Targets

Asteroseismology of pre-main sequence stars has the potential to probe the interior structures of stars in their earliest evolutionary phases and connect to the later stages starting from the zero-age main sequence. For many pre-MS delta Scuti stars discovered from ground-based observations, TESS is now the first space mission delivering the high-quality, nearly uninterrupted photometric time series to fully study these stars. The present proposal aims to extend the TESS 2-minute cadence data of pre-MS delta Scuti stars to the Northern Hemisphere and includes 65 targets mostly discovered from long cadence FFI data of the TESS Primary Mission. As delta Scuti pulsations can be as short as 15 minutes, we apply for TESS observations with 2-minute cadence.

G04112 Targets

The rapidly oscillating Ap (roAp) stars are rare objects. Nevertheless, they are of unique scientific importance to understand the interplay between stellar magnetic fields and key physical processes, including convection and chemical element segregation. Depending on this interaction, theory predicts that the pulsations may be excited up to frequencies greater than the 2-min cadence Nyquist frequency. Here, we propose to use the 20-sec cadence TESS capability to observe all 31 roAp stars and 6 strong roAp star candidates in the TESS field of view during cycle 4, to establish the true range of excited frequencies in this class of pulsator. This will be key to test the excitation mechanism and for improving our understanding of the impact of the magnetic field on near-surface convection.

G04114 Targets

The search for life on other planets and an Earth 2.0 has become a prominent area of research in recent years. Exoplanets with both photometric and spectroscopic observations are highly prized, as their combined measurements provide details on planetary compositions and the overall nature of the systems. In this proposal, we ask for 2-min cadence for the KELT-24b and HD 332231b systems. We will combine this with simultaneous spectroscopic observations from the world s leading facilities. Our goal is to determine star-planet alignments and characterise stellar surface magnetic variability. The former is important to validate planet evolution theories, and the latter is imperative to help push the Doppler confirmation of exoplanets towards rocky, temperate worlds.

G04116 Targets

Our group with undergraduate students will obtain orbital solutions of subdwarf B (sdB) stars long period binaries using the pulsation timing methods. The most promising formation scenarios involve close binary star evolution with three different channels, 1. Common Envelope (CE) channel, which produces short period (P= 0.1 10 d) sdB binary systems, 2. Roche lobe overflow (RLOF) channel, which results in long period (450 < P < 1400 d) sdB binary systems, and 3. white-dwarf merger channel, which produces single sdB stars. The orbital parameters of binaries of P > 100 d are difficult to measure with conventional methods as well as proving a single sdB stars' existence, so the observational studies of 2, and 3 are incomplete. Pulsation timing methods is suitable for those researches.

G04123 Targets

TESS is the only instrument available that enables a systematic survey of bright pulsating A and F stars covering a large variety of evolutionary stages, rotation rates, chemical compositions and with strong and weak magnetic fields at an unprecedented precision. This proposal aims at continuing the TESS legacy sample of A and F stars that require the 2-min cadence. The new and old TESS data will be used to determine ages of young delta Sct stars, study the interaction of strong magnetic fields, atomic diffusion and suppression of convection in roAp stars, measure tidal forces in close binary systems by observing one-sided delta Sct stars, study atomic diffusion and pulsations in chemically peculiar Am/Fm stars and study the interactions between rapid rotation and pulsations.

G04125 Targets

The most powerful tests of stellar structure and evolution come from the brightest stars in the night sky, for which complementary observational techniques (such as astrometry, asteroseismology, and interferometry) can be combined. So far, naked-eye stars (V<6) have rarely been observed with high-precision, high-cadence photometry from space telescopes such as Kepler/K2 due to the large number of pixels required to capture the saturated pixel columns. The key goal of this program is to apply the novel technique of 'halo photometry' to perform photometry of extremely bright stars with TESS, and obtain high-precision 2-minute cadence light curves of naked-eye stars.

G04126 Targets

The strange flux-dips found in Kepler data of the star KIC8462852 have given rise to one of the most enigmatic astronomical discoveries in recent time, as no satisfying explanations for these dips have been found yet. The purpose of this proposal is to acquire 20s cadence observations of the star with the TESS satellite in order to explore the star's variability. The rapid and uninterrupted cadence of such TESS observations will provide us with the most time-resolved data set available/obtainable. We will use the TESS time-series to 1) perform asteroseismic analysis to search for coherent delta-Scuti like pulsations and 2) search for new dipping events. We will augment these TESS data with coordinated multi-wavelength observations contemporaneously planned at ground-based observatories.

G04129 Targets

Prior to the era of regular space-based photometry, oscillations in solar-like stars were detectable only through heroic radial-velocity efforts from the ground or, in a handful of cases, from earlier space missions such as WIRE, MOST, and CoRoT. In contrast, Kepler allowed us to determine fundamental asteroseismic parameters for hundreds of main sequence stars as well as thousands of red giants. However, despite these successes, a gap remains at the bottom of the main sequence in the asteroseismic HR diagram. Here we propose to attempt to fill that gap using TESS 20-s cadence data from a large group of M dwarfs. TESS is ideally suited to photometric detection of M dwarf oscillations due to its unique combination of red sensitivity and short observing cadence.

G04131 Targets

We propose analysis of TESS lightcurves and simultaneously obtained optical high-dispersion spectroscopy for stars exhibiting a newly appreciated type of periodic variability. Known members of the ``batwing" or ``complex rotator" lightcurve morphology class are all M-type stars younger than a few tens of millions of years. The sample undoubtedly will expand as examination of TESS data proceeds. Our ground-based program consists of continuous spectra obtained at all phases throughout the short (<1 day) rotation periods. Spectroscopic time series enable more physical constraints on what is causing the unusual and varied patterns in the phased lightcurves of this sample. Specific theoretical predictions of gas/dust entrainment will be tested including magnetic/dynamical shepherding.

G04132 Targets

Megaflares, stellar flares of 10^35 erg, are among the largest and rarest flares emitted by M-dwarfs. They may fully dissociate Earth-like atmospheres in single events. It is currently unknown how their energy is released as a function of time, especially in the UV. We propose 20 s cadence observations of a large sample of megaflares from active stars across the sky to measure their impulsive emission profiles, coupled with simultaneous ground-based observations of a subset of events to measure flare temperature and constrain UV emission. This will be the first statistically-robust survey of megaflares at high cadence.

G04133 Targets

With space asteroseismology we can measure the internal rotation of evolved stars. However there are a range of theoretical predictions of angular momentum transport and loss that are reasonably consistent with these small number of results. In order to distinguish between physical models, we require stars of known core and surface rotation rate. Experience with Kepler has demonstrated that asteroseismology can simultaneously constrain the internal and surface rotation rates with sufficient data, and so we are requesting additional observations of 237 carefully characterized subgiant stars in the northern continuous viewing zone to make this possible. This powerful sample will permit tests of gyrochronology and stellar angular momentum evolution theory, and it has other broad applications.

G04134 Targets

Polaris, the current North Pole Star, is the brightest Cepheid in the sky, and features a dominant pulsation period of approximately 3.974 days. As the prototypical Classical Cepheid, the star has served as a laboratory for studies of the period-luminosity relationship, stellar pulsation, and massive star evolution for more than a century. Ironically, despite this concentrated study - and over 1100 ADS publications - much remains uncertain about this valuable astrophysical laboratory, including its mass, radius, age, and evolutionary state. TESS provides a unique and crucial opportunity to clarify this confusing situation and to test the stability of Polaris' light amplitude as well as the presence of additional short-timescale variability previously reported for the star.

G04135 Targets

Active galactic nuclei (AGN) are the among the most extreme objects in the universe: galaxies with a central supermassive black hole feeding on gas from an accretion disk. Because accretion disks are challenging to image, variability is among the only direct probes of this physics. Our program will produce consistently-treated, transparently-reduced optical light curves of a large sample of X-ray selected AGN to explore whether AGN exhibit distinct disk geometries during radio-loud and radio-quiet phases, search for QPOs, develop clean proxies of black hole mass, and study the variability of complex AGN sub-types. We will also produce a public pipeline, quaver, especially developed for AGN, as well as our reduced light curves as a public legacy sample.

G04137 Targets

We propose a mix of ultrafast (20-second-) and fast (2-min-cadence) observations of more than 5200 known or candidate white dwarfs visible in Cycle 4 of the TESS mission. Our proposed 20-second observations will enable asteroseismology of a large sample of known and high-likelihood pulsating white dwarfs, continuing the space-based revolution into the interiors of pulsating white dwarfs. We will also search these white dwarfs for transits of other stars or even remnant planetary systems with at least 2-min-cadence observations; transits of Earth-sized white dwarfs are likely to be very deep but also very short, just a few minutes, requiring high-speed observations.

G04138 Targets

Planet Hunters (PH) and PH TESS have proven successful at crowd-sourcing visual inspection of Kepler and TESS light curves to detect long-period exoplanet (LPE) candidates that would be invisible to traditional automated searches. With PH classification of all Kepler M-dwarf light curves completed, we seek 2-minute cadence TESS observations of 4110 of these targets and 62 other known LPE candidate hosts in the Kepler field to create light curves to be injected into the PH TESS interface. With a specialized pipeline that includes an injection/recovery study, we will 1) identify new LPE candidates, 2) refine properties of previously reported candidates in the sample, and 3) constrain the occurrence rates of LPEs around M-dwarfs with a unique methodology.

G04139 Targets

The intense ultraviolet (UV) emission from stellar flares has given them a pivotal role in the habitability of exoplanets around active M stars. However, current habitability studies often use white-light measurements to predict the UV effects of flares, by assuming the optical blackbody flare spectrum can be extrapolated into the UV. We propose to test the accuracy of these UV predictions by combining white-light flare rates measured from TESS 20 second cadence observations with the observed flare activity in near- and far-UV GALEX lightcurves for a set of M stars. With these combined observations we will confirm whether studies that depend on white-light flare rates can accurately predict the UV flaring behaviour of M stars and thus the UV environments of the planets they host.

G04140 Targets

We propose to observe the benchmark K2-138 system with 2-minute cadence observations to measure transit timing variations. K2-138 is one of a small but extremely valuable set of systems for which the planet masses can be measured with both transit timing variations (TTVs) and precise radial velocity (PRV) measurements; fewer than 10 such systems are currently known. Having simultaneous and complementary TTV and PRV observations leads to tighter constraints on the masses, compositions, and eccentricities [1]. K2-138 represents a promising new laboratory for studying multi-planet dynamics.

G04142 Targets

Flare studies are now measuring how the magnetic activity of low-mass stars changes with age, however it is not known whether these age-dependent white-light flare rates accurately trace the evolution of ultraviolet (UV) flares. We propose to obtain 20 second cadence lightcurves for 122 K and M stars previously observed with the Hubble Space Telescope (HST), to measure white-light flare rates. These stars range from pre-main sequence to field age stars and include stars associated with the Hyades cluster. By comparing how the UV and white-light flare rates change with age and testing whether white-light rates can accurately predict the flare behaviour in the UV, we will provide an insight into the contribution of flares to the UV environments of exoplanets, both young and old.

G04147 Targets

With thousands of transiting exoplanets detected to date our search will enter a new era of discovery with upcoming large telescopes that will look for signs of life on these transiting worlds. Here we reverse the viewpoint and ask which stars have a vantage point that allows them to have seen Earth s vibrant biosphere when it transits the Sun? We propose to observe the closest 845 stars within 100 pc that could have spotted life on Earth since earliest recorded human civilization about 5,000 years ago the same way we plan to on nearby transiting exoplanets. Only TESS is capable of searching these stars in the ecliptic effectively for transiting planets in cycle 4, including rocky planets in the Habitable Zone, that could detect life on our transiting Earth as well.

G04148 Targets

In the age of wide-field photometric exoplanet surveys, the number of planet candidates has rapidly outpaced the resources available to perform radial velocity (RV) followup and mass measurements. Stellar activity remains a major barrier to detecting terrestrial-mass planets, and prevents ultra-precise Doppler spectrometers from utilizing their full instrumental precision. Astronomers need tools to predict the RV variability, or jitter , in order to select quiet targets that are most amenable to RV followup. We aim to use TESS light curves to develop a photometric diagnostic for RV jitter in fully-convective M stars. Such a diagnostic has already been demonstrated for Sunlike stars, but is unstudied in M dwarfs, which are of high interest as potential host stars to habitable exoplanets.

G04149 Targets

Starspot-induced rotational modulation produces light curves with fixed period, but with amplitudes that depend on the spot contrast, which itself is wavelengh dependent. We propose a systematic approach to quantify the slope of starspot contrast evaluated between the overlapping Kepler and redder TESS passbands. We will target the large sample of 10^4 to 10^5 spotted stars observed in K2 and to-be-observed in TESS Cycle 4. The approach will deliver constraints on plausible starspot temperature contrast as a function of spectral type and rotation rate. We will use only FFIs which are adequate for measuring amplitudes and periods. The non-contemporaneous nature of K2 and TESS requires a large number of head-to-head sources to average over cosmic variance due to stellar activity cycles.

G04150 Targets

We propose the search for and characterization of discrete mass-loss events (outbursts) in northern Be stars (initiated in TESS Cycle 2) as well as in Be stars observed during the Kepler/K2 mission. Rapid rotation alone cannot explain the ejection episodes, and non-radial pulsations (NRP) have been proposed as an explanation. Our goal is to verify the correlation between the NRP regime and the feeding of the envelope by combining ground-based spectroscopy data to identify outbursts and the measurement of small changes in pulsation frequencies with TESS 2-min cadence observations. Fourier analysis of photometric data is performed using a methodology developed for CoRoT and K2 Be stars.

G04151 Targets

Blazars are a class of active galactic nuclei characterized by non-thermal emission from a relativistic jet, with extreme variability properties. Their unpredictable flux changes occur on time scales from minutes to years. It has been claimed that the short-term variability can have a double nature, the fastest events possibly due to energetic processes in jet substructures, while on longer time scales we may see the effect of orientation changes. We propose 2-min cadence TESS observations of one BL Lac object, S5 0716+714, and one flat-spectrum radio quasar, 3C 279. Both sources are optically bright and well-known for their multiwavelength activity. The aim is to dissect the flux behavior on different time scales to reach a deeper knowledge of blazar emission and jet structure.

G04152 Targets

This proposal argues for observations of three cataclysmic variables (CVs) at 20-second cadence and for two CVs at 2-minute cadence. The three high-cadence targets were observed during Cycle 2. Observations of those targets are requested to probe at six-times-higher cadence both normal dwarf nova and stunted novalike outbursts. Observations at two-minute cadence are requested for two objects not observed with TESS -- one exhibits stunted bursts while the other is a high-magnetic system. The long nearly uninterrupted data sets provide of order 100 eclipses to investigate accretion behavior. Eclipsing systems directly probe the accretion disk and the response of the disk to bursts.

G04156 Targets

In our search for habitable worlds, M dwarfs have become prime targets. However, they harbor explosive stellar flares, impacting their exoplanets' surface habitability. The field thus needs a robust calibration for deriving X-ray/UV flare energies from TESS flare energies. Hence, we propose a timely pilot study to observe TESS's three most flaring M dwarfs synchronously with TESS 20s cad. and Swift, gaining continuous coverage across X-ray/UV, and optical wavelengths. We selected the top three targets possible, and with 33.3ks (9.3h) of Swift time per target, we have >80 100% statistical chance per target to catch one or more flares synchronously with TESS and Swift. Our program will open the door to one of TESS's primary mission goals: truly understanding M dwarf worlds.

G04157 Targets

M-dwarfs are enticing targets for small transiting planets in the habitable zone. TESS will find hundreds, some bright enough for atmospheric probing by JWST. However, the field is frustrated by poor constraints on the host M-dwarfs. We aim to solve this with 161 eclipsing binaries comprised of F/G + M stars, all with 11+ years of spectroscopy to unveil masses and metallicities. We now require TESS short cadence light curves to obtain primary and secondary eclipses, and hence measure the radius and temperature. We request 2-minute observations and funding such that we can develop the most comprehensive sample of M-dwarfs known, significantly refine the empirical mass-radius-metallicity-temperature relation, assisting both exoplanet hunters and stellar modellers

G04165 Targets

AM CVns are binaries with 5 < Porb < 68 mins in which a white dwarf (WD) accretes He-rich material from another WD or a He star. AM CVns are rare systems. Until now we know 58 objects, of which 40 have shown outbursts, which are not well understood. Recent studies that include more data and exclude upper limits have shown that the relation Porb and superoutburst duration is much flatter than previously believed. Likely the relations between Porb and the recurrence time, and the amplitude are strongly affected by upper limits as well. This has implications for accretion models in AM CVns. For TESS Cycle 4 we request monitoring of 30 AM CVns at 20sec cadence to study their outbursts, in particular enhance mass-transfer mechanisms, and to study flares and flickering in persistent systems.

G04168 Targets

A new class of M dwarfs with strict, periodic complex modulations has recently been identified. These complex rotators have light curves exhibiting sharp features on short timescales; the periodicity of these features is sometimes well beyond the Nyquist limit of the TESS FFIs. Moreover, these stars' flux modulations exhibit stark changes over time periods of months to years. The most promising models able to explain such variations center on the occultation of stellar features by co-rotating dusty material. This proposal is requesting short-cadence data for six such targets in the North and the ecliptic. Short-cadence data for these targets will enable us to track the changes in these stars' light curves at various epochs and refine existing models for this intriguing class of stars.

G04171 Targets

Eclipsing binary stars (EBs) serve as fundamental astrophysical laboratories for studying thermodynamical properties of stars and their interactions. TESS is providing us with an unprecedented all-sky photometric sample of bright EBs. By continued observing of ~2200 EBs in Sectors 40-55 with the 2-min cadence, we will acquire a long temporal baseline of observations that allow us to study some of the most pressing questions in binary star physics: what drives multiplicity rates, what determines mass ratio distributions, and what is the impact of binarity on stellar evolution. We also propose using the 2-min cadence targets as a training set for the classifying neural network to harvest ~1 million EB lightcurves from Full Frame Image (FFI) data and disseminate them to the public.

G04174 Targets

TESS is a revolutionary tool for studying transients but only if the transients are first discovered and characterized from the ground due to the delay in the release of TESS data. We will use the All-Sky Automated Survey for Supernovae to identify TESS transients, our team's access to 2m-8m telescopes in characterize them, and our team's broad expertise to analyze them, including the TESS data. There are guaranteed results for both thermonuclear and core-collapse supernovae, and high probabilities of novae, tidal disruption events and blazar flares.

G04176 Targets

We propose to obtain TESS 2-minute cadence data to monitor 31 of the James Webb Space Telescope (JWST) spectrophotometric standard stars for variability. These stars are necessary to accurately calibrate the absolute and relative flux JWST receives across its range of infrared wavebands. By monitoring these stars we will look for evidence of brightness variations due to flares, pulsations or stellar spots. Additionally, we will check whether star light is occasionally blocked by planets, other stars, or dust. TESS' all-sky survey has given us the opportunity to easily monitor the photometric stability of standard stars, which will enable the JWST calibrations team to provide the best possible calibrations of the JWST observations.

G04177 Targets

Here, we propose to use densley sampled TESS 2-minute cadence data to discover eclipsing carbon-oxygen white dwarfs which have been absent from discoveries made using ground based surveys due to their significantly lower sampling rate. We use the recently released Gaia EDR3 astrometry to produce a list of candidate DWD binaries which are overluminous compared to the normal WD cooling sequence.

G04178 Targets

While TESS is optimized to discover small planets orbiting nearby, bright stars, its observing strategy is not optimized to detect planets in the Habitable Zone (HZ). We have identified a small set of stars for which the prime mission TESS observations permit the observation of multiple transits of a planet within the star s HZ. We propose 2-minute observations of the subset of those stars that are observable in Cycle 4. These additional observations will permit the detection of smaller planets in the HZ, the detection of planets orbiting further out in the HZ, and improve the ability to follow-up and confirm HZ transit candidates.

G04179 Targets

In contrast to their quiet lives on the main sequence, post-main sequence evolution provides an opportunity to study the response of planets to changing irradiation, tides and mass loss. Moreover, the oscillations of such stars can be used to precisely measure both stellar and planet properties. We propose to continue the first all-sky survey to detect and characterize giant planets transiting evolved stars using TESS full-frame image (FFI) data. We select stars that allow both asteroseismology and planet transit detection using 10- and/or 30-minute cadence data. This program will allow us to address the occurrence of giant planets as a function of stellar mass, metallicity and evolution, and the mechanism(s) responsible for the inflation and engulfment of highly irradiated planets.

G04180 Targets

Sun-like stars are born with relatively rapid rotation and strong magnetic fields. Through a process known as magnetic braking, the rotation slows over time as stellar winds gradually remove angular momentum from the system. Recent observations suggest that the efficiency of magnetic braking may decrease dramatically in stars near the middle of their main-sequence lifetimes. One hypothesis to explain these observations is a shift in magnetic complexity from predominantly larger to smaller spatial scales. By combining asteroseismology from TESS with ground-based spectropolarimetry, we propose to constrain the timing and duration of the shift in magnetic complexity for a carefully selected sample of stars that are near or beyond the middle of their main-sequence lifetimes.

G04181 Targets

Using TESS observations with a 2-minutes cadence, we propose to carry out a homogeneous and accurate study of stellar activity, stellar rotation, and variability in the Taurus-Auriga star-forming region, which is an excellent laboratory to study young stellar objects and planet formation. The data will include about 67% of the known low mass members in Taurus. We will study the frequency, duration, intensity, and morphology of stellar flares and the relations with stellar rotation and other stellar activity indicators. We will classify light curves identifying variability caused by accreting disks (dippers or bursters) and by stellar spots and obtain rotational periods for periodic or semi-periodic light curves. We expect to get a better insight into the interplay between stellar activity.

G04182 Targets

Small close-in planets come in one of two flavors: rocky super-Earths and enveloped terrestrials with extended H/He envelopes. For M dwarf planetary systems, it remains unclear whether this transition arises from thermally-driven atmospheric mass loss or if it is the natural by-product of rocky planet formation in a gas-poor environment. We propose to identify the formation pathway by gathering precise radial velocity measurements with the HARPS-N spectrograph of five keystone planets located within the radius valley. By deducing whether these planets possess gaseous H/He envelopes, we will uncover the dominant emergence pathway of the radius valley around M dwarfs.

G04184 Targets

Our understanding of stellar pulsation, and RR Lyrae variables specifically, has seen exciting new discoveries from space-based data. Additional, small amplitude, frequencies were found in their Fourier analysis. These are associated with higher-order radial and non-radial pulsation modes. Recent claims are some may be found in all RRc/RRd. A possible connection between one of these and the Blazhko effect is also found, which if true, could help solve the longest and most difficult mystery of stellar pulsation (and maybe all of astrophysics). We will use TESS data to examine the Fourier analysis of RR Lyrae lightcurves in detail, characterize these additional frequencies, find their ubiquity in a representative sample from the Galaxy, and search for any possible link to the Blazhko effect.

G04185 Targets

Pre-main-sequence binary stars provide opportunities to test our understanding of stellar astrophysics by confronting models with observations. Young eclipsing binaries allow precise measurements of stellar masses and radii, providing stringent tests of pre-main-sequence evolutionary models. Short-period young binaries that are accreting from circumbinary protoplanetary disks allow tests of our understanding of disk accretion and angular momentum exchange. Both types of systems are relatively rare but have clear photometric signatures, making TESS ideally suited for their discovery, especially when combined with existing ground-based surveys that have pre-selected young binary stars. We propose a search for examples of these high-value targets using TESS two-minute-cadence lightcurves.

G04186 Targets

Solar and stellar flares often show pulsations and oscillatory signatures in their emission, collectively known as quasi- periodic oscillations (QPOs). This phenomenon is closely linked to flare energy release. TESS' new 20s cadence mode is a step-change in capability and provides a new unique opportunity to detect and analyze such pulsations. We will analyze flares from a set of active M-dwarf stars and address the following questions: 1. What is the prevalence of QPO signatures in stellar flares, and how do they depend on source star properties? 2. Do stellar QPOs display the same relationships with the host flare as their solar counterparts? 3. Is there consistent scaling between solar and stellar QPOs? 4. Can we use QPO signatures to perform stellar coronal seismology?

G04187 Targets

We propose to observe the active, flaring, mid-M dwarf star AF Psc at 20-second cadence with TESS during Sector 42, combined with simultaneous X-ray and ultraviolet observations at high cadence with Swift. We will attempt to measure the energy partition and temperature evolution of at least one flare simultaneously across several electromagnetic regimes at very high time resolution.

G04188 Targets

M dwarfs comprise 75% of stars in the Galaxy and frequently host small planets. They are prime targets in exoplanet searches, especially those focused on finding habitable, Earth-like planets. However, M dwarfs are strongly magnetically active, sending high-energy radiation and charged particles at their planets during frequent flaring events. These events influence atmospheric chemistry, and the strongest are predicted to make life on nearby planets difficult, if not impossible. It is therefore key to understand M dwarf activity. Overlap between K2 and TESS Cycle 4 targets yield an unprecedented opportunity: we propose to map out time- and mass-dependent trends in magnetic activity on decadal timescales for a statistical sample of M dwarfs spanning a variety ages and masses.

G04189 Targets

TESS Cycle 4 observations will produce extensive datasets that will result in thousands of additional candidate exoplanet transit signals from which we can expect hundreds of new planet candidates. The established method to vet these signals are based on a semi-manual vetting process that starts with a Robovetter triage code and follows with a more accurate manual vetting. Instead, we propose to use an accurate, reliable, and explainable deep neural network (DNN) designed by mimicking how human vetters utilize all unique elements of a data validation report in order to identify different types of false positives before vetting a TCE. Our model also provides an accurate disposition score so that the domain scientists can focus on the most likely planet candidates for follow up study.

G04190 Targets

A large number of non-interacting black holes are expected to exist close to the solar system that have so far been evaded detection in X-rays. We propose to perform a focused search for the gravitational self-lensing signature using TESS Cycle 4 data in order to make the first discovery of a detached compact object with a stellar companion or, in the absence of a detection, distinguish common envelope formation from field binaries. Detection of these objects will enable studies of their population characteristics and merger histories, complementing studies via gravitational waves. We plan to perform a computationally efficient, GPU-accelerated, compherensive search for black holes binaries in the TESS FFIs down to the 15th magnitude to determine the occurrence rate of these objects.

G04191 Targets

Of the millions of stars that TESS will observe during Cycle 4 in either FFIs or 2-minute cadence, less than 3% are well suited to radial velocity follow up with current precision RV instruments. We propose to obtain 2-minute TESS photometry of 48,431 stars in the Northern Ecliptic Hemisphere and Ecliptic Plane whose Teff, log(g), and V- or T-mag make them viable RV candidates. Planets found to orbit these stars will have the best chances of obtaining precision mass measurements. Such measurements will make these planets prime targets for future atmospheric characterization with ground-based facilities such as HPF and NIRSPEC, as well as space-based missions including HST, JWST, and ARIEL. Of these stars, 34,570 (71.4%) have not been previously observed at 2-minute cadence by TESS.

G04195 Targets

We aim to maximize the TESS mission s yield of long-period exoplanets by upgrading a half-meter telescope to constrain the periods of single transit signals found by TESS. We will identify single transit planet candidates (STPCs) previously identified from Cycle 2 that re-transit in Cycle 4. After calculating the discreet set of possible transit windows, we will use a robotic and automated half-meter telescope to strategically observe the possible transit windows to uniquely determine the periods of dozens of long-period planet candidates. Once the period is uniquely determined, the orbits and masses of these STPCSs will be measured, and these new additions will improve our understanding of the composition, dynamics and formation of long-period planets.

G04200 Targets

Many white dwarfs have been found to have their surfaces "polluted" by remnant rocky bodies from their progenitors' planetary systems. These polluted white dwarfs are our best observational probe of exoplanet interior chemical compositions, which they can reveal with exquisite sensitivity. However, without a good understanding of the origins of white dwarf pollution, it is impossible to fully leverage the information about chemical compositions from the pollution on their surfaces. Using TESS we will study the origins and process of white dwarf pollution by identifying transiting disintegrating minor planets on their way to polluting white dwarfs. This will help to properly interpret the information about planetary compositions from the surfaces of white dwarfs.