TESS Approved Programs

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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 .

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

AM CVns are binaries with 5
Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

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.

Target List

We propose to use the unique capabilities of TESS to characterize at least 1-2 TDEs and 20+ TDE host galaxies in Cycle 4. Pre-peak TESS observations of TDEs will allow us to measure precise rise times and constrain the properties of the disrupted star and the black hole, while data after peak light will be used to search for changes in the accretion flow and constrain the decay time. We will also use pre- and post-flare TESS light curves of TDE hosts to search for AGN activity and examine the effects TDEs can have on their environments. We request 25ks of Swift observations to be triggered on a TDE candidate being observed by TESS, providing blackbody temperatures and luminosities concurrent with the TESS observations.

Target List

In the coming years, our ability to characterize the atmospheres of small planets will significantly improve as multiple next generation telescopes and missions are expected to begin operations. Unfortunately, most of the known transiting planets, those particularly valuable for atmospheric studies, have ephemerides that have degraded too much to efficiently schedule observations on these expensive facilities. We propose to globally fit observations from TESS and K2, with any available ground-based radial velocity measurements, for all known planets originally discovered by K2 and have transits detected by TESS. We will release a catalogue of refined ephemerides and system parameters to the community and create self-consistent sample of exoplanet parameters for population studies.

Target List

We propose to observe a large sample of magnetic cataclysmic variable stars (MCVs) to study variations in their rates of mass-transfer. Our target list includes two types of MCVs: polars and intermediate polars. With polars, we will characterize the timescales over which the rate of mass-transfer can either shut off or restart, with the aim of testing theoretical predictions about the cause of this poorly understood phenomenon. With intermediate polars, we will examine how the dynamical nature of the accretion flow onto the white dwarf is impacted by variations in the mass-transfer rate. In-depth observations of these unpredictable phenomena are possible only with continuous, high-cadence observations of a large number of targets, making TESS optimal for this study.

Target List

The star J005311 is suspected to be the product of a merger of two white dwarf stars. Its spectrum is unique and spectacular, displaying broad emission lines of five-times ionized oxygen. The line widths suggest a wind expanding at 16000 km/s, more than 5% of the speed of light. The wind is seen to have density fluctuations that vary on a times scale of minutes and there are overall brightness changes at the 5% level. In the future, as the wind removes angular momentum from the merged white dwarfs, the remnant may reach a critical density and explode as a supernova. This program proposes to search for the spin frequency of the merger using the 20-sec cadence of TESS. The star's magnetic field may couple its rotation to the wind resulting in a persistent, but weak, photometric signal.

Target List

We propose to use TESS 20-second cadence data to study flares on 61 M dwarfs most of which are known to exhibit high flare rates during TESS Cycle 2 and K2 observations. This is the first time a large and systematic study of the flares on M dwarfs will be performed using higher cadence data. We will use this data to i) build more accurate flare frequency distributions (FFDs) for a wider range of flare energies, ii) study variation of flare rates as a function of spectral types and ages, iii) develop flare model based on more precise rise and decay time scales, iv) develop flare analysis software which will make flare studies more convenient in future, and v) study relations between energies of flares observed on highly active M dwarf (GJ 3631) in optical, UV and X-ray wavelengths.

Target List

Studies of small close-in planets have revealed a gap in the radius distribution whose central location shifts to smaller sizes with decreasing stellar mass. Thermally-driven mass loss and gas-poor formation models can explain the existence of the radius valley but make distinct predictions regarding its location versus stellar mass. Because these model discrepancies are greatest around the lowest mass stars, 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. The comparison of these measurements to the valley around Sun-like stars will enable the distinction between the competing physical models and will establish what physics drives the sculpting of the close-in planet population around M dwarfs.

Target List

We propose to identify variable AGN and quantify their rapid optical variability on tens of minutes to hours timescale using the high-cadence 10 min data from cycle 3 and 4. The goal is to derive the dependence of the black hole mass on the variability properties at these fastest timescales and compare it with predictions from state-of-the-art models for AGN accretion disks. Additionally, we will perform the first systematic search for optical quasi-periodic oscillations (QPOs) in all known variable AGN. Any detected QPOs would allow us to constrain the spins of the black holes. TESS is currently the only facility that can provide the uniform, high-cadence data required for the success of this program. We will make all the light curves and the entire transient detection pipeline public.

Target List

While classical novae have been known to arise from thermonuclear runaways on the surface of white dwarfs, recent multi-wavelength observations have revealed a shocking new picture involving multiple outflows and powerful shocks that shape every aspect of the eruption. We propose to utilize the novel capabilities of near-infrared surveys to find highly obscured novae together with the red sensitivity of TESS to characterize their multi-wavelength variability across all timescales. Combining TESS light curves of an expected 4 Galactic novae with a dedicated ground based follow-up campaign, we will establish for the first time, the diversity of shocks and outflows in novae as a function of viewing angle and white dwarf mass, and illuminate their effects on the evolution of the binary system.

Target List

Gyrochronology is a promising yet flawed clock. Recent studies of open clusters revealed that stars do not spin down continuously. Instead, once stars converge onto tight sequences of slowly rotating stars, they temporarily stall for an unknown but extended period of time. This phenomenon can heavily bias rotation-based ages for low-mass K and M dwarfs. We propose to conduct a census of stellar rotation in nearby (d<400 pc) young (<1 Gyr) clusters, moving groups, and stellar streams with the goal of determining when these tight sequences form, and how long stars remain stalled, as a function of mass. We will use FFI data to extract light curves for ~5000 stars distributed across dozens of coeval groups for this purpose.

Target List

Although the flare rates of stars have been well-studied as a function of spectral type, they are much more poorly understood as a function of stellar age. We will use a sample of 400 wide white-dwarf main-sequence (WD-MS) binaries to extend the flare-activity-age relations for low-mass stars using high-fidelity ages (10-30%) from their white dwarf companions. We will leverage these binary systems to investigate the evolution of flare rates with time past 1 Gyr, for the first time with precision ages. Quantifying the flare rate in old stars provides a timeline within which to examine questions about the impact of stellar activity on exoplanet habitability.

Target List

We propose to observe nearby, coeval, wide binary systems as fundamental astrophysical calibrators for period-age relations for low-mass (< 0.8 Msun) main sequence stars. We target systems where solar-like oscillations should be detectable in TESS in the F/G primary star, enabling a precise asteroseismic age determination (10-20%), and where the secondary star is of K or M spectral type. 68 such binary systems meet these criteria and are visible in Cycle 4, roughly doubling the sample of asteroseismic age calibrators for period-age relations, and providing the first large sample of seismic calibrators for low-mass stars.

Target List

Stellar atmospheres encompass an abundance of waves and oscillations. This includes those driven by flares. Oscillatory and pulsating signatures, commonly known as quasi-periodic pulsations (QPPs), are observed at many wavelengths during both solar and stellar flares and are observed in the flare decay branch in stellar light curves. These phenomena travel on the magnetic field lines in the star's atmosphere. We propose a study of oscillations within flares to place constraints on the interpretation and understanding of the fundamental processes operating in both solar and stellar flares at different layers within the stellar atmosphere. We propose 51 TESS 20-sec data of M-K-G highly active stars and simultaneous data for Swift and TESS 20-sec cade for 3 highly active stars for the study.

Target List

The formation of hot Jupiters (HJs) can be constrained by the existence of closely-orbiting small companions to HJs. Previous searches have found only three HJs with nearby companion planets, but only a fraction of every known HJ system has been observed at a short 2-minute cadence with the photometric precision of TESS. We propose to observe all Cycle 4 HJs with TESS's 2-minute cadence in a search for small nearby companions that could help constrain the formation mechanism of HJ systems and calculate the multiplicity rate of this unique planet population. This would generate the first complete and uniform data set of almost all HJ systems down to the precision of TESS, allowing for more detailed population analysis of this mysterious class of planets.

Target List

We propose to complement TESS core science by adding hundreds of new long-period planets and candidates. We will search Cycle 4 for additional transits of single-transit planet candidates (STPCs) found in Cycle 2 and in K2. We aim to significantly increase the current sample of warm and cold giant exoplanets, and to generate a sample of the coldest M dwarf planets. We will also identify new STPCs in Cycle 4. These candidates will be released to the community to allow efficient follow-up. This program will provide giant planets that will be amenable to follow-up studies, enabling constraints on the composition and formation of long-period exoplanets. As added value, this program will allow us to update the occurrence rates of long-period giant exoplanets.

Target List

The Event Horizon Telescope (EHT) observations of the supermassive black hole (SMBH) in M87, has provided a powerful experimental testbed for strong gravity. Hence the SMBHs in several nearby systems, including the SgrA*, are all potential candidates to enhance our understanding of gravitation in such extreme environments. However, providing strong constraints on several aspects of the accretion and jet physics in active galaxies that are possible through multiwavelength observations, is vital for the convergence of theoretical simulations of accretion processes. We thus propose a TESS monitoring campaign of ten nearby galaxies, probing for the orbital variability time-scale. Besides, we also seek to address the role of the magnetic field based on the turbulence of the light curves.

Target List

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 models requires a sample of EBs that spans both mass and age. TESS provides the first dataset capable of finding EBs on this scale. We therefore propose for targeted 2-m cadence observations of 40 young EB (10-700 Myr) discovered by our team in Cycle 2 and for 4157 young association members that will receive their first TESS observations in Cycle 4.

Target List

We propose to obtain 2-minute cadence observations of over 4000 young stars located in 25 nearby associations and open clusters with ages spanning 1 Myr - 3 Gyr. Young planets detected in these groups can constrain key processes that drive the early evolution of planetary systems and inform our understanding of various trends observed in the older exoplanet population. Stellar activity plays an important role in this evolution, especially at young ages. We will search for young transiting planets and characterise the early evolution of stellar flare activity to inform our understanding of early planetary system evolution and subsequent (potential) habitability.

Target List

We propose to search for rapid periodic variability in a sample of high-mass white dwarfs to look for white-dwarf merger remnants. Finding and characterizing a population of bona-fide merger remnants by searching for rapidly rotating and highly magnetized white dwarfs can help us understand the properties of remnants and their evolution, as well as understand the origin of magnetic fields in white dwarfs. Additionally, finding the merger rate of white dwarfs below the Chandrasekhar mass can provide important constraints on type Ia supernova rates and on the rate of close double degenerate binaries that will be detected with LISA, as well as help characterizing the contribution to the LISA sensitivity curve by the low-signal-to-noise double degenerates background.

Target List

Wolf 359 is a nearby late-M dwarf that is one of the most active flare stars in our solar neighborhood. Observations from the K2 mission revealed many hundreds of flares within an 80 day timespan, along with numerous unresolved small flares. TESS' 20-sec mode is ideal to resolve the flares from Wolf 359 and obtain precise measurements of the flare rates and energies of this star. We propose to obtain TESS 20-second cadence optical data and simultaneous Swift X-ray and ultraviolet data. The combined data will provide a deeper understanding of its flares in unprecedented detail, enabling us to identify relations between optical, UV, and X-ray flares, and thus provide a broad view of the underlying mechanisms and origins of the stellar activity.

Target List

The formation of hot Jupiters (HJs) can be constrained by the existence of closely-orbiting small companions to HJs. We have already conducted a small-scale search for these companions in the available Cycle 1 TESS 2-minute cadence data, finding no new planets, but only a fraction of every known HJ system was observed at this cadence. We propose to observe all Cycle 5 HJs with TESS's 2-minute cadence in a search for small nearby companions that could help constrain the formation mechanism of HJ systems and calculate the multiplicity rate of this unique planet population. This would generate the first complete and uniform data set of HJ systems down to the precision of TESS, allowing for more detailed population analysis of this mysterious class of planets.

Target List

We propose to use the Tull Coude Spectrograph of the McDonald Observatory 2.7m Harlan J. Smith Telescope to obtain precise radial velocity measurements of selected TESS Objects of Interest with potential transiting giant planets in order to obtain excellent orbit determinations and planet characterizations. Our proposed orbital determinations of hot- and warm-Jupiters and Saturns will add significantly to the known population of well characterized objects. We will place particular emphasis on determining which of these objects have non-zero eccentricities by specifically targeting appropriate orbital phases. We will search carefully for indications of additional planets (either inner or outer) in the HJ and WJ systems that we confirm, and place limits on their presence where none are

Target List

TESS has revolutionized the study of short-period exoplanets by discovering transiting worlds around some of our closest and brightest stellar neighbors, but its impact on longer-period systems has been limited by the short observational baselines. Until we better characterize these cooler planets, which have been less impacted by photo-evaporation than their hotter counterparts, and some of which may even be hospitable to life, we cannot fully understand the processes that sculpt planetary populations and the prospects for life outside the solar system. We propose an extensive Key Project to identify and characterize two times more long-period exoplanets in TESS Extended Mission 2 relative to TESS primary and first extended missions, and enable follow-up observations of these worlds.

Target List

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, as identified in the Astro2020 Decadal. We aim to solve this with 227 eclipsing binaries comprised of F/G/K + M stars, with 12+ years of spectroscopy to unveil masses and metallicities. We require TESS light curves to measure the radius and temperature. We request short cadence 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 modelers.

Target List

Gyrochronology is a promising yet flawed clock. Recent studies of open clusters revealed that stars do not spin down continuously. Instead, once stars converge onto tight sequences of slowly rotating stars, they temporarily stall for an unknown but extended period of time. This phenomenon can heavily bias rotation-based ages for low-mass K and M dwarfs. We propose to conduct a census of stellar rotation in nearby (d<1000 pc) young (<1 Gyr) clusters, moving groups, and stellar streams with the goal of determining when these tight sequences form, and how long stars remain stalled, as a function of mass. We will use FFI data to extract light curves for ~5000 stars distributed across dozens of coeval groups for this purpose.

Target List

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 boundary mixing. 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.

Target List

Ultra-hot Jupiters UHJs present many observational opportunities and theoretical conundra. Their large masses and short periods facilitate follow-up, particularly of radial velocities (RVs). Observational evidence points to ongoing tidal decay of their orbits, demanding an accurate and expanded catalog for long-term monitoring, and their phase curves evince highly dynamic meteorology involving disassociation, ionization, and magnetic fields. We propose to use Cycles 1 through 5 TESS data, leavened with ground-based observations, to validate or confirm possible UHJs already identified as ``planetary candidates'' on the Exoplanet Archive.

Target List

The calibrated full-frame images (FFIs) acquired by TESS provide a unique opportunity to study large-scale diffuse emission in the Universe. This proposal will create as a product for the community deep co-added mosaics of the TESS FFIs acquired in all sectors released through Cycle 5, and Jupyter notebooks and Containers that will offer access to them and enable replication of the results. The computations will be performed on the Elastic Cloud 2 of Amazon Web Services and will be underwritten with credits already in place. The processing will exploit mature, scalable Open Source tools: the Montage image mosaic engine, operating with the Pegasus Workflow Manager to orchestrate the processing and HT Condor to run jobs.

Target List

TESS has discovered many planet candidates via single transits and duotransits, whereby two transits are separated by a large data gap. These discoveries are the best pathway toward increasing TESS's sample of long-period giant planets, which have cooler temperatures and probe different pathways of migration and heavy element accretion. Yet, further characterization of these planets is hindered by their unknown orbital periods. We propose to refine the ephemerides of TESS single transit and duotransit planet candidates through observations from the Unistellar Citizen Science Network, which consists of 7,000 eVscopes around the world. The Network's longitudinal coverage makes it uniquely suited for long duration transits and poised to enhance the scientific legacy of the TESS mission.

Target List

We propose an acid test of two "gold standard" methods for deriving ages of main sequence stars with ages greater than roughly 1 Gyr. We will obtain TESS 20 second cadence observations of old stars in wide-separation binary systems with a white dwarf, derive ages for the star from asteroseismology, then compare to ages independently estimated for the white dwarf companion. This will serve as a validation and cross-check for the usage of both methods as accurate chronometers and pave the way for making age estimates for as many single nearby old stars as possible.

Target List

M dwarfs are the most common stars in the galaxy and have a high frequency of Earth-sized planets at an equilibrium temperature that places them in the habitable zone, making them favored targets of upcoming missions to detect and characterize exoplanets. We propose to obtain 20-sec cadence TESS observations of a volume-limited sample of 23 nearby M dwarfs, which we will complement with simultaneous ALMA ACA or SMA millimeter observations. The results of this proposal will increase the sample of stars observed simultaneously with optical and millimeter wavelengths considerably and allow us to study correlations and trends for a statistically significant sample.

Target List

We propose to accurately measure the gamma-ray optical lags in flaring blazars by jointly analyzing TESS FFI and Fermi-LAT light curves. The radiation mechanism for the high energy spectral component of blazars is currently under debates. While SED fitting is in general not sufficient to distinguish between models, the geometrical constraints provided by timing analysis can provide new constraints to break the degeneracy. The proposed analysis will significantly increase the sample of lag measurements by a factor of several compared to existing measurements, enabling us to measure the lag distribution between the synchrotron and high energy blazar emission components and provide geometrical constraints that can distinguish models for blazar emission at MeV to TeV range.

Target List

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 program, >150 of which are available for TESS in Cycle 5. The light curves will be combined with the precise radial velocity (RV) measurements in order to obtain accurate and precise, absolute stellar parameters.

Target List

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.

Target List

It has become unclear in recent years how a planet can survive the late stages of the stellar evolution of low- and intermediate-mass stars. Recently, thanks to the TESS mission, it has been discovered a planet candidate, similar to the mass of Jupiter and ten times its mass, orbiting a white dwarf (WD) star, which demonstrates that planets can avoid being tidally disrupted by their host star. However, the proportion of planets that can survive being tidally disrupted by their host star or planets that survived the common envelope stage is unknown. In order to address these questions, a selection of hot-WD (Teff>50kK), as obtained from a spectral energy distribution analysis (from UV to optical) and public catalogues, are being proposed to be observed by the TESS mission on its Cycle 5.

Target List

WASP-33b is a benchmark planet for studying hot Jupiters. The gas giant has been studied extensively for over a decade due to its excellent signal to noise (m_TESS=7.87) and because it is representative of many of the fascinating properties of hot Jupiters. However, the host star is a rapidly-rotating $\delta$ Scuti pulsator, which introduces complex additional signals into photometry and complicates parameter estimation. We therefore propose to independently test several key characteristics of WASP-33b by performing a joint transit and asteroseismic analysis using Cycle 5 data. Our analysis will yield improved constraints on the host star's bulk density, rotation rate, oblateness, inclination, and temperature, and will provide independent constraints on WASP-33b's nodal precession.

Target List

Cometary dust trails represent an important transport mechanism for delivering dust and organics from the outer Solar system to the terrestrial planets. TESS, with its wide field of view and ability to reveal faint structures in coadded observations, is an ideal tool for studying these phenomena. We propose to use full-frame images from Cycle 5 to perform a study of dust trails, using the observations to constrain trail models that will derive the dust grain properties and the parent comet production rates. Twenty-three periodic comets will appear in Sectors 56-69, and ~15 of them will exhibit trails. The number of trails available offer a statistically significant sample that will produce meaningful constraints on cometary contributions to the Solar system dust inventory.

Target List

The host star of the WASP-33 exoplanet system is a rapidly rotating delta Scuti star. It was recently detected that WASP-33 is experiencing tidally perturbed oscillations in g modes and likely caused by the spin-orbit misalignment of the system. The wavelet map of the frequencies < 5 1/d shows vivid amplitude and frequency modulations in the timescale ~1.5 2 orbits. The 20 sec cadence observations will enable us to examine the wavelet-map of WASP-33 at the higher pulsational frequencies. We can also investigate the precession of WASP-33b and reconstruct the full phase curves that will lead to better constrains of the interior. The better sampling of 20 sec cadence data will give more accurate times of mid-transits, so enable us to carry out more thorough transit timing variation analysis.

Target List

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 970 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 of a variety of accreting compact objects.

Target List

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 lightcurves of 51 F, G, K and M type targets. We will combine the TESS lightcurves with archival and new ground-based spectroscopic observations from the world's leading facilities. Our goal is to determine for the first time/refine 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.

Target List

We propose to monitor well known photometric standard stars from the HST/CALSPEC database to identify significant variability from pulsations, spots and flares using the TESS 2-minute data. This database is used to calibrate astronomical images in the optical and infrared, including telescopes like Spitzer and the James Webb Space Telescope (JWST). These stars are necessary to accurately calibrate the absolute and relative flux across different instruments and observatories, a requirement for precise astronomical measurements. TESS has already shown its value in identifying variability larger than 1 percent in a subset of these stars. Here we request to search for variability on stars yet to be observed by TESS and monitor the rest for unexpected variability.

Target List

Late-type M dwarf exoplanet systems are ubiquitous and open new doors for detailed atmospheric characterization. However, TESS alone is less effective for ultra-cool stars, and so the community needs to establish collaborations with ground-based surveys. We here propose a joint effort to observe 280 carefully selected, nearby (< 40 pc) late M dwarfs with 20 s cadence in Cycle 5. We select targets where TESS can detect temperate Earth-sized planets with SNR>3 and the ground can immediately confirm them. This strongly expands TESS' reach and impact to the most interesting targets for JWST and the ELTs. As a free byproduct, we can study stellar flares on an under-explored sample in unprecedented detail, adding pivotal data on the interaction between stars and planets.

Target List

In cycle 5, TESS will be decreasing the full frame image (FFI) exposure time to 200s, from 600s. This leap in cadence will significantly enhance our ability to explore white dwarf astrophysics across a range of science cases. Here we propose to extract lightcurves of the one million out of 1.4 million white dwarf candidates from Gaia eDR3Fusillo2021 that will be visible during TESS Cycle 5, and perform a thorough analysis of these lightcurves using a suite of period finding algorithms, and making both the lightcurves and power spectra produced from this program publically available.

Target List

The Sun's 11-year cycle of surface magnetic activity strength is an essential observation in understanding the origin and mechanics of magnetic dynamos in stars. Rates of stochastic flares on the Sun are observed to vary by at least an order of magnitude from activity cycle maximum to minimum. Flares should therefore be one of the highest-amplitude indicators of activity cycles for nearby stars. We propose to analyze 2-min light curves for 736 dwarfs that previously had at least 20 flares observed by TESS. By generating per-Sector flare rates, and leveraging the now 5-year baseline of TESS, we can study activity cycle variation on months to years timescales.

Target List

We propose 2-min cadence observations of 6914 young stars located in 93 nearby associations, co-moving groups and open clusters with ages spanning 1 Myr - 2 Gyr. Young planets can constrain key processes that drive the early evolution of planetary systems and inform our understanding of various properties observed in the older exoplanet population. Stellar activity plays an important role in this evolution, especially at young ages. We will search for young transiting planets and characterise the early evolution of stellar flare activity to understand the subsequent diversity and habitability of planetary systems. We additionally propose 20-sec cadence observations of 37 potentially young TOIs to facilitate detailed transit and flare analyses in these systems.

Target List

Recent pebble accretion models have estimated that the occurrence of Earth/super-Earth planets (1-4 Rearth) peaks around stars with masses 50% the mass of the Sun, and decreases for smaller stars, citing TRAPPIST-1 and Teegarden's Star as rare systems. We propose 20-second and 2-minute cadence observations for a magnitude-limited (Tmag < 13) sample of stars with masses between 10%-30% the mass of the Sun, which will mitigate issues with pointing jitter in FFIs. We discuss that higher cadence observations of the brightest very-low-mass stars will add an additional 1-5 planets in Cycle 5, doubling the yield expected from FFI frames. This magnitude limited sample, which was systematically built, will provide stronger constraints on the planet occurrence rate for the lowest-mass stars.

Target List

Tidally tilted pulsators are stars in tight binary systems whose pulsation axis is pulled into alignment with the binary's tidal axis. The first four tidally tilted pulsators were all discovered with TESS, and there is now conclusive proof that TTPs can occur in evolved stars. However, many unanswered questions about TTPs remain, including why only certain stars in tight binaries exhibit TTPs, and others do not. With this proposal, we seek short-cadence data to study tidally tilted pulsations in a set of candidates identified during prior stages of the TESS mission. This will allow for the first comprehensive census of TTPs and will allow for the inference of population-level properties of these unique stars.

Target List

The transient sky is ripe for TESS. The FFIs are not only a treasure trove for exoplanet and stellar science, but they also present a great opportunity for the transient community. In Cycle 5 TESS will uniquely produce high-dynamic range, high-cadence 200-second FFI light curves for large amplitude, bright transients. We have developed two FFI pipelines using the first ~4 years of data and we will continue to improve these pipelines to better correct for systematics. Here we propose to bring the lightcurves to the people by creating a TESS FFI light curve server that is publicly accessible, easy to use, and utilizes an interface already familiar to a large fraction of the community.

Target List

Recent studies have shown that K stars undergo a period of prolonged elevated ultraviolet (UV) activity. The UV emission from flares is an important part of this picture, yet K stars have been overlooked relative to M stars. To estimate the UV activity of K stars current studies must either use UV flare rates measured for M stars, or extrapolate white-light measurements into the UV. We propose to test the accuracy of these UV predictions by combining white-light flare rates measured from TESS 20-s cadence observations with the observed flare activity in near-UV GALEX lightcurves for 4379 main sequence K stars. We will assess whether studies using white-light flare rates can accurately predict the UV flaring behaviour of K stars and thus the UV environments of the planets they host.

Target List

The relationship between rotation, convection and stellar activity is a key challenge for stellar physics and exoplanet habitability. We propose to measure rotation periods and spot modulation amplitudes for a large (~1000 projected detections) sample of FFI TESS targets with star spot filling factors inferred from high-resolution spectroscopy. We will infer the dependence of spot filling factor on metallicity and Rossby number with 1,500 dwarf targets, 415 with simultaneous light curves and spectroscopy. Our 1,000 evolved active stars (300 simultaneous) will be a powerful resource for population studies and the correspondence of single and binary star activity. Simultaneous data allows us to map TESS spot modulation amplitude to star spot filling factor, which has broad applicability.

Target List

We are requesting 20-second TESS cadences to search locations of white dwarf stars from Gaia eDR3 for periodic light curve signals from small, habitable exoplanets. Expected periods for habitable zone planets orbiting cool white dwarfs would be around 0.5 to 4 days. Planets transiting white dwarf stars would have deep transits that should be detectable even though the stars are relatively faint at 16 to 18 mag. Any planets discovered will be excellent candidates for JWST observations of exoplanet atmospheres.

Target List

We propose to continue the search for and characterization of discrete mass-loss events (outbursts) in Be stars located in TESS observation fields (initiated in TESS Cycle 1) 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 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 is performed using a methodology developed for CoRoT and K2 Be stars.

Target List

It is often assumed that X-ray variations in AGN drive UV/optical variations by heating the outer parts of the accretion disk. However, AGN X-ray and UV/optical light curves are often poorly correlated, which challenges this assumption. We can test whether or not AGN UV/optical variations are reprocessed X-rays by searching for a correlation between X-ray reflection features measured by NICER and optical variations measured by TESS; such a correlation must exist if X-ray reprocessing drives AGN variability. Simultaneous TESS and Swift data can also constrain the total reprocessed energy and predict the X-ray reflection strength, which provides a second test. We propose coordinated observations of Mrk 359 with TESS, NICER, and Swift to carry out these tests of X-ray reprocessing.

Target List

The local volume around the Sun is a laboratory for studying all aspects of star and planet formation. ESA's Gaia telescope is revolutionizing our understanding of co-moving associations and TESS is well placed to complement efforts to understand kinematic structures and the window they provide on stars and planets. In Cycle 5 TESS will observe 21340 sources that span 84 different kinematic structures within 1kpc. We propose to use this data to (1) measure new rotation rates (2) better classify complex rotators, (3) and ultimately determine the gyrochronology relations across 1Myr - 1Gyr in discreet age bins. We plan on making our catalog of over 20,000 rotation rates available in a young star database containing all complimentary astrometric, kinematic, and chromospheric youth indicators.

Target List

Asteroseismology is one of the most powerful tools to study the interior and fundamental properties of stars. Oscillations have not yet been detected at the lowest-mass end of the main sequence, although they were predicted several years ago. TESS has a unique combination of red sensitivity and short observing cadence, which makes it ideally suited to photometric detection of M dwarf oscillations. If detected, these would be a true breakthrough in oscillation detection. M dwarf oscillations would also provide an independent way to estimate mass, radius and effective temperature, which could help fix the existing discrepancies between observations and models. In this proposal we attempt to measure M dwarf oscillations using the TESS 20 second cadence data on the best targets available.

Target List

Coordinated multi-wavelength photometry and spectroscopy is essential for the characterisation of flares and their contribution to the high energy environments of low-mass stars. However, professional facilities are limited to a few nights of observations, limiting analysis to small samples. In contrast, amateur astronomers can observe targets for weeks and can obtain photometry and spectroscopy simultaneously with TESS, allowing us to measure the temperatures and emission line energies of larger samples of white-light flares. We propose for 20-s cadence photometry of 9 active K and M stars that can be simultaneously observed by amateur astronomers, to study and characterise these energetic events. This target list will be made public for use by our team and the wider amateur community.

Target List

We propose to use the unique capabilities of TESS to probe Tidal Disruption Events (TDEs) and their host galaxies, building a more complete observational picture of TDEs. TESS provides high-cadence, high-precision photometry unequalled by any other observatory. We expect TESS to detect 2+ TDEs in Cycle 5, and TESS data obtained at or before peak light are useful for constraining the properties of the star and the black hole, while data taken after peak can be used to search for short timescale variability that indicates changes in the accretion rate. Existing pre-flare TESS observations of the host galaxies of 10+ additional TDEs found in Cycle 5 will be used to search for signs of host variability and the presence of an underlying AGN.

Target List

AM CVns are binaries with 5< Porb <70 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 70 objects, of which 45 have shown outbursts, which are not well understood. Recent studies that exclude upper limits have shown that the relation Porb and superoutburst duration is much flatter than previously believed. Likely the relation between Porb and the recurrence time is strongly affected as well. This has implications for accretion models in AM CVns. For TESS Cycle 5 we request monitoring of 51 AM CVns at 20sec cadence to study their outbursts, in particular, to study the superhump evolution and further investigate the presence of enhance mass-transfer mechanisms recently identified in these binaries.

Target List

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.

Target List

We propose TESS monitoring of ~100 Green Pea galaxies (GPs) to test for Active Galactic Nuclei. GPs are low-luminosity, low-mass, compact galaxies with extremely strong emission lines including [OIII], Lyman-alpha, and lines of highly ionized species. They are the best known analogs of the low-mass, early galaxies that powered cosmological reionization, and show a higher variability fraction than other dwarf galaxies. TESS Cycle 5 data will allow uniquely precise and accurate variability monitoring on time scales varying from hours to years, important for identifying low mass nuclear black holes, and in large enough numbers to constrain the AGN fraction in Green Peas. We will use AGN-customized pipeline to average Full Frame Images on hour timescales to study sources as faint as 20th mag.

Target List

The only star where flares can be directly imaged and resolved remains our Sun, and yet stellar flares shape exoplanets and might drive their habitability. It is thus crucial to leverage all-sky data and gain a demographic picture of how these physical processes can be translated to other worlds. We propose observing TESS' 50 most flaring stars with 20 s cadence and the 1,000 next most flaring stars with 2 min cadence to fulfil two major goals: (1) better understanding the activity properties of these most extreme flaring stars, and (2) searching for exoplanets orbiting them.

Target List

A key innovation of the first TESS extended mission was the introduction of 20-second data, which shows up to 30% better photometric precision than 2-minute data for bright stars due to differences in cosmic ray rejection algorithms. We propose to use 20-second data to improve transit parameters for all bright (T<10mag) TESS Objects of Interest and search for small planets around the brightest stars that may have been missed using 2-minute data in the prime mission. Our program will yield improved radii and orbital eccentricities for several key exoplanet systems, including planets slated atmospheric studies with JWST, and may lead to the detection of a transiting planet around the brightest star to date.

Target List

Stellar atmospheres encompass an abundance of waves and oscillations driven by flares. Oscillatory and pulsating signatures, commonly known as quasi-periodic pulsations, are observed at many wavelengths during both solar and stellar flares and are observed in the flare decay branch in stellar light curves. These phenomena travel on the magnetic field lines in the star's atmosphere. We propose a multiwavelength study of oscillations within flares on solar-type stars to place constraints on the interpretation and understanding of the fundamental processes operating in both solar and stellar flares at different layers within the stellar atmosphere. We propose 48 TESS 20-sec data of highly active G-K stars and simultaneous TESS-Swift-NICER data for 4 highly active flaring stars for this study.

Target List

Removal of systematics from light curves is critical for all TESS research. Existing approaches are demonstrated on limited sets of targets selected to present the advantages of the particular method. Thus, no comprehensive analyses have been performed to determine their validity on large, commonly selected samples. We propose to extend the capabilities of a software toolkit that is being developed to compare correction approaches and apply it to large samples of different target types that cycle 5 will provide from all cadence observations, 20-s, 2-min, and particularly 200-s FFIs. This will produce statistical conclusions on which technique performs best on each target class and set of instrumental effects. The software will be publicly released to facilitate community analyses.

Target List

TESS Objects of Interest suffer from high false-positive rates due to the large (21") pixels of the TESS detectors. Without ground-based photometric and spectroscopic follow-up, one cannot be confident in the planetary nature of many TESS candidates, nor can one be confident that costly PRV and atmospheric observations will succeed. We propose a Key Project to use a select set of premier ground-based facilities to observe primarily small (Rp < 4 Re) TOIs identified in TESS Cycles 5, 6, and 7, rule out NEBs, detect false positives, and refine orbital and physical properties of the system. These observations are crucial for planning PRV and atmospheric observations. We will also support TFOP and TESS GI proposed observations of other interesting targets as available telescope time allows.

Target List

Solar-type stars - 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 the small amplitudes and fast timescales of oscillations in solar-type stars only a small number of detections have been made using space-based photometry. Here we propose to use the unique 20-second cadence capabilities from TESS to establish a benchmark sample of bright asteroseismic solar-type stars, which will enable us to (i) investigate the connection between magnetic activity cycles and stellar age in solar-type stars and (ii) characterize the fundamental properties of exoplanet host stars.

Target List

The calibration of empirical ages based on rotation, chromospheric emission, and lithium requires data from benchmark star clusters. The large gap in age between the Pleiades (120 Myr) and Praesepe (670 Myr) can be filled by previously unappreciated clusters that now have enhanced memberships from Gaia. We propose to measure periods from ZTF light curves, complementing those from TESS by reaching longer periods and fainter stars. We will also collect large samples of high-resolution spectra for each cluster. In summary, we will (1) establish 7 clusters as new benchmarks for stellar astrophysics using new [Fe/H] data, (2) produce extensive kinematic, rotation, activity, lithium, and other abundance data for a large number of their members, and (3) retune rotation, activity, and Li clocks.

Target List

We propose to operate an existing pipeline to provide calibrated target pixels, light curves, and full transit search results for more than 150,000 targets per sector selected from the TESS Cycle 5 200 second cadence FFIs. We will provide a machine learning (ML) vetted list of planet candidates from the transit search.

Target List

The metal-poor populations of stars in the Milky Way encode the history of chemical enrichment, galactic creation and destruction. Because of the location of the Kepler field, these stars generally do not have the sort of precise asteroseismic characterization we have come to expect for metal-rich benchmarks, and problems have been noted when comparing to models. TESS has already identified more such stars and with new data from TESS Cycle 5, the majority of these stars will have sufficient data for detailed measurements. We therefore propose to perform an asteroseismic analysis for ~1000 metal poor stars, and to provide a catalog of results including masses and ages, as well as information for stars from interesting populations, including stellar streams associated with galaxy mergers.

Target List

The discovery of circumbinary planets (CBPs) was a breakthrough over a decade ago. They are a unique comparison sample to single-star planets, testing the limits of planet formation. Slightly more than a dozen planets have been found, but the field has plateaued, limited by rudimentary by-eye detection methods and Kepler's limited sky coverage. Only with TESS and the latest automated Stanley detection algorithm can we more than double the number of CBPs. In addition to individually interesting new systems, our TESS sample will enable a broad study of the occurrence rate, habitability and formation of CBPs. Brighter stars will also assist RV follow-up, which was recently demonstrated for CBPs for the first time.

Target List

We propose an acid test of two "gold standard" methods for deriving ages of main sequence stars with ages greater than roughly 1 Gyr. We will obtain TESS 20 second cadence observations of old stars in wide-separation binary systems with a white dwarf, derive ages for the star from asteroseismology, then compare to ages independently estimated for the white dwarf companion. This will serve as a validation and cross-check for the usage of both methods as accurate chronometers and pave the way for making age estimates for as many single nearby old stars as possible.

Target List

Complex periodic variables (CPVs) are a type of variable star whose root cause is not understood. Possible explanations include transiting dust clumps; stellar prominences; or misaligned, low-mass debris disks. We propose to use the Cycle 6 FFIs to make light curves for all T<16 K- and M-dwarfs within 100pc. By searching these stars for new CPVs, we expect to double the sample of known CPVs within 100pc. We will also release the light curves to MAST. Independently, we propose that new 2-minute observations be acquired for CPVs that we have found in the Cycle 1-5 2-minute data, to determine how CPV variability changes over thousands of cycles. These efforts will advance our understanding of M-dwarf evolution, including perhaps the evolution of debris disks and young rocky planets.

Target List

Young multi-planet systems are heterogeneous in terms of planet radii and orbital spacings, while older planets show a high level of internal similarity. This difference suggests that intra-system uniformity arises from evolutionary, rather than formative processes. However, we are far less sensitive to small planets in young systems than old ones. In many young multi-planet systems, a planet hiding just below our detection threshold could explain away some of the differences. To explore this, we propose for higher-cadence TESS data of known young planetary systems. The new data and better cadence, combined with improved light curve extraction and search methods, will increase our sensitivity by 20-50%. With this, we can separate out effects of evolution and detection biases.

Target List

Massive stars are important chemical factories in the Universe and progenitors of core-collapse supernovae. However, a major limitation of stellar evolution models is their uncalibrated prescriptions for interior rotation and mixing processes. This is because we lack detailed empirical constraints on massive star interiors. Fortunately, most massive stars pulsate in pressure and gravity modes, which are highly sensitive to a star s interior physics. The TESS mission is providing the first set of long-duration and high-precision light curves for a large sample of massive stars. In this project, asteroseismology applied to 2-min TESS light curves will allow us to mitigate the large rotation and mixing uncertainties in stellar evolution theory.

Target List

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 return 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 6 (~5 SNe total) and will utilize new tools to spectroscopically classify SNe minutes after discovery. This follow-up data, including access to high cadence Swift ultra-violet light curves, will break model degeneracies inherent to the single-band TESS data alone.

Target List

The extant sample of young (<1 Gyr) planets have radii statistically larger than their older counterparts. Unfortunately, detection biases against finding planets around young stars makes it hard to study the underlying physical drivers of this change. Mass measurements for young planets are critical, but radial velocity surveys of young systems are often overwhelmed by stellar activity. A technique that can overcome this challenge is Transit Timing Variations (TTVs). We aim to search for TTVs in 38 systems known to host young planets. Several already show TTVs or have periods near mean-motion resonances. This project will aid in elucidating the underlying physical processes driving planet size evolution and contribute to our overall understanding of planetary formation and evolution.

Target List

The large majority of AGN are "radio-quiet," and the origin of their apparently ubiquitous radio emission is not understood. Theories for its origin include weak jets, shock interaction of a radiative outflow with nuclear interstellar gas, and most intriguingly, the radio counterpart of the X-ray source commonly referred to as the "corona." The relationship between the corona and the accretion disk represents a major gap in our understanding of AGN central engines. We propose to use awarded time on the VLBA, in addition to the requested TESS and NICER observations, to definitively confirm or rule out the coronal origin theory and motivate a new multi-wavelength means of investigating causal relationships in the central engine.

Target List

With the detection of thousands of brown dwarfs (BDs) to date, the field of substellar objects has developed significantly since the discovery of Teide 1 in 1995. However, there are still open questions concerning their formation and evolution processes. In order to understand BD formation and evolution in more detail, it is necessary to explore the diversity of BD population properties. The purpose of this project is twofold. First, we aim to extend the number of known transiting BDs and to re-analyse previously known systems using new TESS data combined with Gaia DR3 parallaxes. Second, we plan to search for asteroseismic signatures of confirmed BD host stars and to assess their fundamental parameters using advanced stellar modeling and scaling relations.

Target List

TESS light curves show the entire orbital phase curve, including the transit, secondary eclipse, and sinusoidal phase modulations. Those modulations are shaped by atmospheric processes in the planet s atmosphere and by star-planet gravitational interaction. We propose to extend to Cycle 6 our ongoing systematic study of TESS phase curves. Combining Cycle 6 data with that of previous Cycles will extend the time baseline of TESS data, allowing to look for variations in planetary atmospheric properties, and, result in higher quality phase curves. Our project maximizes TESS s science by extracting all information encoded in the light curves.

Target List

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 ~200 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.

Target List

We propose 20-s cadence observations of 9 bright (V~11) and active K and M stars that will be simultaneously observed with the facilities of amateur astronomers. The TESS observations will be combined with ground-based spectroscopy and B and V band photometry to measure flare color temperatures, the energy released via line emission, and distinguish changes in the continuum from emission-line enhancement during flares.

Target List

A tidal disruption event (TDE) occurs when a star is ripped apart by a supermassive black hole (SMBH). Many TDE models are sensitive to the early-time TDE emission, a phase that is poorly constrained. We propose to use the high cadence and high precision photometry of TESS to probe the early phases of TDEs, which encodes information on the disrupted star and central SMBH. Strong constraints on TDE rise times and slopes will inform theoretical models on how the first light from TDEs is produced. We will also use TESS to place deep limits on the variability of TDE host galaxies and understand potential AGN activity. We expect TESS to detect at least 2 new TDEs in Cycle 6 during flare and that there will be at least 10 additional TDEs with pre-flare TESS observations of their host galaxy.

Target List

The TESS Northern Continuous Viewing Zone (NCVZ) in Cycle 6 will provide the longest high-cadence space photometry of stellar populations to date, making it an exceptional region for red giant asteroseismology. Far-reaching observations in the NCVZ will uniquely capture the stellar variability of many stars within the Galactic thick disk and halo populations that were only sparsely explored by previous asteroseismic surveys. We propose to measure the stellar pulsations of red giants in the NCVZ using Full Frame Images to determine their asteroseismic ages. Supplemented by present large spectroscopic surveys, these measurements will shed light on the formation history and development of old Galactic populations at much broader spatial scales than ever before.

Target List

Stellar companions and exoplanets in wide orbits are poorly understood, in particular around intermediate-mass stars for which spectroscopic radial velocities cannot be precisely measured. We propose to use pulsation timing variations to map orbits around the intermediate-mass delta Scuti variable stars, probing both exoplanets and binary companions. The method is immune to data gaps and increases in sensitivity with the orbital period and is thus uniquely suited for the 6-year timebase that will be enabled through TESS Cycle 6.

Target List

While distant solar system bodies are underrepresented in the set of known minor planets, they offer key insights informing the solar system s structure and early evolution. TESS is ideally suited to observe distant minor planets at scale due to its space-based vantage point, near-all-sky coverage, and continuous observing cadence. However, no framework currently exists to systematically extract these signals from the TESS dataset. We propose to develop and release an open-source linear shift-stacking program that will enable the rapid detection and follow-up of solar system minor planets in the TESS dataset, with an emphasis on relatively distant and faint objects in Cycle 6. We will apply the developed framework to report minor planet candidate tracklets for the full Cycle 6 dataset.

Target List

Red giants are expected not to exhibit any significant surface rotation, but some rapidly-rotating red giants (RRRGs) do. Their photometric modulations also suggest surface features of magnetic origin, through a convective dynamo driven precisely by this anomalous rotation. Photometric transients associated with flares, which should in principle also result from this dynamo action, had been observationally inaccessible owing to temporal undersampling at 30-minute cadence, save for a very select few red giants previously targeted at short cadence. The new availability of 200 second full-frame images (FFIs) now permits TESS to probe time-domain magnetic activity of essentially all visible RRRGs in a hitherto observationally inaccessible temporal regime. We propose to study this activity.

Target List

RV searches on stars pre-selected through their anomalously low chromospheric emission prove this property signals the presence of hot planets. Hot planets lose mass, forming a circumstellar gas shroud concentrated around the planet's orbital plane. For edge-on orbits, this gas absorbs in the stellar chromospheric emission lines. Thus the presence of hot, mass-losing planets depresses a star's apparent chromospheric emission. For intrinsically inactive stars, this effect suppresses the chromospheric emission to an impossibly low level. Our target FGK stars have been selected for their anomalously low chromospheric emission. We propose for 20s cadence light curves and 120s FFIs for 8 bright nearby targets expected to be hosts of hot low mass planets in edge-on orbits.

Target List

Our group will use pulsation timing methods to obtain the orbital solutions of long-period subdwarf B (sdB) star binaries and search for single sdB stars. The most promising formation scenarios for sdB stars involve the evolution of close binary systems through three different channels: 1) the Common Envelope channel, which produces short-period (P = 0.1-10 d) sdB binary systems; 2) the Roche Lobe Overflow channel, which results in long-period (450 < P < 1400 d) sdB binary systems; and 3) the white-dwarf merger channel, which produces single sdB stars. Observational studies of the orbital parameters of binaries with P > 100 d and the existence of single sdB stars are incomplete using conventional methods. Therefore, pulsation timing methods are suitable for these research areas.

Target List

TESS Objects of Interest suffer from high false-positive rates due to the large (21") pixels of the TESS detectors. Without ground-based photometric and spectroscopic follow-up, one cannot be confident in the planetary nature of many TESS candidates, nor can one be confident that costly PRV and atmospheric observations will succeed. We propose a Key Project to use a select set of premier ground-based facilities to observe primarily small (Rp < 4 Re) TOIs identified in TESS Cycles 6 and 7, rule out NEBs, detect false positives, and refine orbital and physical properties of the system. These observations are crucial for planning PRV and atmospheric observations. We will also support TESS GI and TFOP proposed observations of other interesting targets as available telescope time allows.

Target List

We propose 2-min cadence observations of 5808 young stars located in 39 nearby associations, co-moving groups and open clusters with ages spanning 1 Myr - 2 Gyr. Young planets can constrain key processes that drive the early evolution of planetary systems and inform our understanding of various properties observed in the older exoplanet population. Stellar activity plays an important role in this evolution, especially at young ages. We will search for young transiting planets and characterise the early evolution of stellar flare activity to understand the subsequent diversity and habitability of planetary systems. We additionally propose 20-sec cadence observations of 30 potentially young TOIs to facilitate detailed transit and flare analyses in these systems.

Target List

The tidally tilted pulsators are a class of oscillating stars in close binary systems whose pulsation axis has been pulled into the orbital plane by the gravitational influence of their companion star. Their value for astrophysical study is rooted in the combination of the strengths of binary star and asteroseismic analyses; pulsational mode identifications can be achieved because the oscillations are visible over nearly 360 degrees of aspect throughout the orbital cycle. Here, we propose 24 of such objects or candidates for 20-sec or 2-min cadence, four for the first time and the remainder for continued observations for deeper study.

Target List

We ask for 20-second cadence data for 38 key targets for flare studies in the context of the ESA-Ariel mission. The targets are either young, M-dwarfs, or known to be highly active. Each hosts at least one planet which is an excellent target for the Ariel mission and these preliminary characterisation efforts will help in the target selection for the mission.

Target List

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 bright transients. We propose to capitalize on the TESS FFIs in cycle 6 in two ways: 1) At its fastest, TESS can only discover transients after downlinking its data. To alleviate this delay, we will observe the full TESS field with an increased cadence (4-6 times per day) using ASAS-SN. 2) We will spectroscopically classify all bright transients discovered in the TESS footprints using the SCAT survey. The combination of the two will allow the community to obtain the crucial multi-wavelength data needed to put the TESS data in context.

Target List

We propose a search for ultrafast novae using full-frame images collected during TESS Cycle 6. Although theoretically predicted and observationally confirmed in nearby galaxies, no such rapidly evolving novae have been identified so far in the Galaxy. Finding local analogs of these extragalactic transients will enable a detailed study of their host binary systems and accurate determination of the total Galactic nova rate, constraining the contribution of novae to the chemical evolution of the galaxy and improving our knowledge of binary evolution pathways leading to Type Ia supernovae.

Target List

Binaries consisting of a white dwarf and a main sequence star are common throughout the galaxy, and provide insight into a range of astrophysical questions such as the activity of M dwarfs and the origins of Type-1A supernovae. Over 3000 have been identified via spectroscopy, but the orbital periods for the majority of those systems are unknown. TESS photometry is the ideal tool to detect the percent-level optical variations induced by reflection, ellipsoidal modulation and starspots that reveal the orbital period. We will survey over 500 systems, expecting to detect at least 100 new orbital periods. We will also calculate flare frequency distributions for the main-sequence stars, comparing them as a function of rotation period with single stars.

Target List

AM CVns are H-deficient accreting white dwarf binaries with 5

We request 20-second cadence data for 33 neutron stars accreting from low mass binary companions to search for their thermonuclear bursts. These bursts start as X-ray flares of durations typically of about 10-100 seconds, and the X-rays then heat the outer parts of the accretion disks so part of their emission is reprocessed into the optical band. The recurrence time of the bursts is set by the time it takes to accrete a pile that heats up enough to trigger CNO burning, and understanding the recurrence time as a function of accretion rate yields key information about nuclear physics. TESS's continuous coverage and wide field are needed to estimate the recurrence times, which have been hard-to-impossible to measure over the 50 years in which these bursts have been observed to date.

Target List

We propose to measure rotation periods, starspot flux amplitudes, and flare rates from the TESS FFIs for stars that will be observed within the northern continuous viewing zone during Cycle 6. Changes in rotation periods, flux amplitudes, and flare rates over the Sectors 73-83 will be used to measure short activity cycles, which are expected for stars with short rotation periods (<20 days). FGKM dwarfs are expected to have rotation periods longer than 0.5 days, such that the cadence of the TESS FFIs are sufficient for measuring changes in timing and flux amplitudes of each stellar rotation. Characterizing stellar activity cycles for a large sample of stars will help reveal their impact on exoplanet atmospheres, uncertainties in stellar properties, and stellar interior processes.

Target List

We propose ultrafast, 20-second-cadence observations of several hundred white dwarfs visible in Cycle 6 of the TESS mission. Our proposed 20-second observations will uniquely 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 also propose to observe a subset of white dwarfs with known rapid variability detected by previous TESS data, including many white dwarfs in eclipsing compact binaries as well as some transiting planetary debris systems. Our proposed science case requires the fastest cadence available from TESS, and will expand the largest catalog of rapid variability in white dwarfs ever created.

Target List

Gyrochronology is a promising yet flawed clock. Recent studies of open clusters revealed that stars do not spin down continuously. Instead, once stars converge onto tight sequences of slowly rotating stars, they temporarily stall for an unknown but extended period of time. This phenomenon can heavily bias rotation-based ages for low-mass K and M dwarfs. We propose to conduct a census of stellar rotation in nearby (d<1000 pc) young (<1 Gyr) clusters, moving groups, and stellar streams with the goal of determining when these tight sequences form, and how long stars remain stalled, as a function of mass. We will use FFI data to extract light curves for ~12,500 stars spread across dozens of coeval groups for this purpose, including 1050 stars in 9 group receiving their first TESS data in C6.

Target List

The calibration of empirical ages based on rotation, chromospheric emission, and lithium requires data from benchmark star clusters. The large gap in age between the 120-Myr Pleiades and 700-Myr Praesepe can be filled by previously unappreciated clusters that now have enhanced memberships from Gaia. We propose to measure periods with ZTF, complementing those from TESS by reaching longer periods and fainter stars. We also collected large samples of high-resolution spectra for each of ten clusters. We will (1) establish each as new benchmarks for stellar astrophysics using newly derived [Fe/H] and reddening, (2) produce extensive kinematic, rotation, activity, lithium, and other abundance data for a large number of their members, and (3) retune rotation, activity, and Li clocks.

Target List

Transit timing variations (TTVs) of exoplanets may indicate a decaying planetary orbit or additional unseen bodies in the system, and TESS is an ideal observatory to search for TTVs. Measurements of orbital decay will help us understand the evolution of the hot Jupiter population but only one hot Jupiter is observed to have a decaying orbit. We propose to search for TTVs in all known hot Jupiter and multi-planet systems observable by TESS in Cycle 6 in high cadence mode. We will also use the TESS full-frame images to update the ephemerides of all planets. These observations will greatly inform theoretical models of orbital decay, provide constraints on the role of orbital resonances in the evolution of multi-planet systems, and yield updated ephemerides to aid in follow-up observations.

Target List

We propose conducting multi-color photometry of highly active bright M and G-dwarf flare stars. We perform simultaneous high-time cadence observations (~20 seconds) with both TESS and ground-based telescopes. Our approach involves the utilization of custom narrow-band filters attached to the Apache Point Observatory's 3.5m and 0.5m telescopes. Our aim is to create an unprecedented catalog of Balmer jump ratios and multi-color emission properties of TESS flares. We plan to investigate how these properties evolve during the flare time, and discuss the physical mechanisms that determine flare heating rates. Our study will enable us to more accurately estimate flare energy and provide a critical constraint for the flare activity emission effects of the host star on the surrounding exoplanets.

Target List

We propose to operate an existing data analysis pipeline to provide calibrated target pixels, light curves, and full transit search results for more than 150,000 targets per sector selected from the TESS Cycle-6 200-second cadence Full Frame Images (FFI). We will provide a machine learning vetted list of planet candidates from the transit search. Our analysis will also generate cotrending basis vectors useful for mitigating systematic errors in any light curves generated from the full frame image data. All resulting data products will be archived as High Level Science Products (HLSP) at the Mikulski Archive for Space Telescopes (MAST).

Target List

While terrestrial planets around M dwarfs are superlative opportunities to search for biosignatures, M dwarfs exhibit extended active phases that impact habitability. While much progress has been made to understand M dwarf activity processes, a clear picture of their stellar winds remains elusive. Fortunately, close binary systems containing a white dwarf and an M dwarf are unique laboratories to measure M dwarf wind rates as wind material accreted onto the WD may be detectable with UV/optical spectroscopy. We propose to target 7 WD-MD binaries to assess their flare rates and orbital periods. These data will deepen our understanding of WD physics, binary star evolution, the connection between M dwarf flare rates and winds, and the joint impact of these processes on planetary atmospheres.

Target List

Combined with precise kinematics, TESS's high-cadence light curves allow for powerful new insights into the Milky Way's dynamical history. One open problem in Galactic dynamics is empirically characterizing the timescale of transient spiral arm passages. Simulations have shown that spiral arm interactions can shepherd young stars from near-circular to eccentric orbits. These leave post-resonance "wrinkles" in kinematic-space, which have now been observed with the Gaia mission. With photometry from TESS and gyrochronology, we will measure rotation periods and infer ages for young, low-mass stars in wrinkles. This, for the first time, will place upper-limit timestamps on the most recent spiral arm passages in the Milky Way and improve our understanding of dynamical evolution in the disk.

Target List

Hot Jupiters (HJs) display atmospheric wind structures unique to this class of planets. They are also hot enough to host clouds, which affect the atmosphere's thermal structure and may drive observable variability. We propose to uniformly constrain albedos and assess variability for a sample of 24 HJs with multiple sectors of TESS phase curves. For at least 6 HJs in our sample, we can compare phase curve measurements of equatorial jet velocity with constraints from phase curves. We may even break the degeneracy between albedo and jet velocity for targets that are expected to have such a degeneracy from energy balanced models. We aim to validate a preliminary positive correlation between albedo and dayside temperature and seek evidence of temporally varying cloud coverage and advection.

Target List

Solar-type stars - 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 the small amplitudes and fast timescales of oscillations in solar-type stars only a small number of detections have been made using space-based photometry. Here we propose to use the unique 20-second cadence capabilities from TESS to establish a benchmark sample of bright asteroseismic solar-type stars, which will enable us to (i) investigate the connection between magnetic activity cycles and stellar age in solar-type stars and (ii) characterize the fundamental properties of exoplanet host stars.

Target List

A key innovation of the first TESS extended mission was the introduction of 20-second data, which shows up to 30% better photometric precision than 2-minute data for bright stars due to differences in data processing algorithms. We propose to use 20-second data to (i) improve transit parameters for all bright (T<10mag) TESS Objects of Interest and (ii) search for small planets around the brightest stars that may have been missed with 2-minute data. Our program will yield improved radii and orbital eccentricities for several key exoplanet systems, including many confirmed multi-planet systems and several sub-Neptune systems slated for atmospheric studies with JWST. Furthermore, our program may lead to the detection of a transiting planet around the brightest star to date.

Target List

TESS Cycle 6 provides a critical extension to the TESS and K2 baselines specifically for complex rotators in benchmark clusters across the ecliptic including the ~2Myr star forming complex in Taurus and the ~25Myr Beta Pictoris moving group. Using Cycle 6 data alongside previous observations in K2 as well as Cycles 1-5, we will investigate the longevity of 10 known complex rotators as well as search for new sources among the ~2000 young M dwarfs that will be observed in Cycle 6. The extended baseline of TESS will lead to more conclusive understanding of the physical mechanism for these outstanding sources revealing whether they are from co-rotating material around the stars or from intrinsic physical changes specific to M dwarfs.

Target List

The extant sample of young (<1 Gyr) planets have radii statistically larger than their older counterparts. Unfortunately, detection biases against finding planets around young stars makes it hard to study the underlying physical drivers of this change. Mass measurements for young planets are critical, but radial velocity surveys of young systems are often overwhelmed by stellar activity. A technique that can overcome this challenge is Transit Timing Variations (TTVs). We aim to search for TTVs in 39 systems known to host young planets. Several already show TTVs or have periods near mean-motion resonances. This project will aid in elucidating the underlying physical processes driving planet size evolution and contribute to our overall understanding of planetary formation

Target List

The discovery of circumbinary planets (CBPs) was a breakthrough over a decade ago. They are a unique comparison sample to single-star planets, testing the limits of planet formation. Slightly more than a dozen planets have been found, but the field has plateaued, limited by rudimentary by-eye detection methods and Kepler's limited sky coverage. Only with TESS and the latest automated Stanley detection algorithm can we more than double the number of CBPs. The addition of cycle 7 is more essential for a CBP study than for a study of planets around single stars, owing to the typically long-period orbits of CBPs. In addition to individually interesting new systems, our TESS sample will enable a broad study of the occurrence rate, habitability and formation of CBPs. Brighter stars will also ass

Target List

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, as identified in the Astro2020 Decadal. We aim to solve this with 326 eclipsing binaries comprised of predominantly F/G/K + M stars. 15+ years of spectroscopy has unveiled masses and metallicities. We now require TESS light curves to measure the M dwarf radius and temperature. We request short cadence 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 modelers.

Target List

Spots and similar features on stars can contaminate efforts to measure the masses, radii, and atmospheres of planetary systems. This is a particular problem for young stars, yet such systems are high-priority targets for JWST. Unfortunately, spot properties vary with age and stellar type, and we do not know what kind of complementary observations are required to extract spot properties. Here we propose a ground-based campaign simultaneous with TESS Cycle 7 observations of five young planet hosts. Our campaign will include observations over multiple rotation periods, which we will use to extract empirical spectra of the surface and spotted region of the star. We can then explore how reliably we can infer the stellar surface as a function of the data type and quality.

Target List

TESS light curves show the entire orbital phase curve, including the transit, secondary eclipse, and sinusoidal phase modulations. The depth of the secondary eclipse and the shape of the phase modulations are determined by the planet's atmospheric properties. We propose to extend to Cycle 7 our ongoing systematic search for temporal atmospheric variability on short-period planets. This is motivated by theoretical expectations and observational claims. Combining Cycle 7 data with that of previous Cycles will extend the time baseline of TESS data and allow looking for variations in planetary atmospheric properties, and, result in higher quality phase curves. This work maximizes TESS s science by extracting all properties encoded in the light curves, and search for their temporal variability.

Target List

Solar-type stars -- 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 the small amplitudes and fast timescales of the oscillations in solar-type stars only a small number of detections have been made using space-based photometry. Here we propose to use the unique 20-second cadence capabilities from TESS to establish an all-sky benchmark sample of bright asteroseismic solar-type stars, which will enable us to: (i) investigate the connection between magnetic activity cycles and stellar age in solar-type stars and (ii) characterize the fundamental properties of exoplanet host stars.

Target List

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/CSM interaction, or an unusual nickel distribution. Despite the unique role of TESS, to maximize its science return 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 7 (~3-5 SNe total), and will utilize new tools to spectroscopically classify SNe minutes after discovery. This array of follow-up data, including access to high cadence Swift ultra-violet light curves, will break model degeneracies inherent to the TESS data alone.

Target List

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 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 unravelling the optical variability properties of a variety of accreting compact objects.

Target List

The background signal in TESS FFIs combines multiple effects, including Earth and Moon s scattered light, lens and CCD reflections. These effects combine to create a composite background signal that is strong and varies in time. The TESS data reduction pipeline does not correct the background in FFIs and current extraction pipelines focus mainly on creating light curves. These pipelines rely mostly on local estimations of the background or do not account for all its components. This leads to losing 10-30% of light curves due to suboptimal background modeling. In this proposed work we will use a neural network model to predict the FFI background. This model will be able to provide background values for the entire CCD image or small cutouts, enabling users to work with FFIs at different lev

Target List

We will use TESS Cycle 7 observations, in conjunction with archival TESS data, to characterize stellar flare rate variability in 14,268 Continuous Viewing Zone stars. From these long baseline flare studies, we will search for traces of activity cycles. We have developed a pipeline to characterize flare rates and perform injection-and-recovery testing, characterizing flare rate completeness never before done on a large scale. Our sample selection of continuous viewing zone stars enables us to both constrain activity variations on years timescales (i.e.\ between TESS Cycles), and on short timescales (i.e.\ between TESS Sectors). This will be the first systematic study of flare activity variations on both short- and long-timescales.

Target List

Massive stars are important chemical factories in the Universe and progenitors of core-collapse supernovae that enrich the host galaxy. However, a major limitation of stellar evolution models is their uncalibrated prescriptions for interior rotation and mixing processes. This is because we lack detailed empirical constraints on massive star interiors. Fortunately, most massive stars pulsate in pressure and gravity modes, which are highly sensitive to a star's interior physics. The TESS mission is providing the first all-sky, long-duration and high-precision light curve data set for the largest ever sample of massive stars. In this project, asteroseismology applied to 2-min TESS light curves will allow us to mitigate the large rotation and mixing uncertainties in stellar evolution theory.

Target List

The rapidly oscillating Ap (roAp) stars provide an exceptional laboratory to study the interplay between fundamental stellar physical processes, such as convection, rotation, atomic diffusion, magnetic fields, and pulsations. However, there are only 121 roAp stars, representing just 5.5% of the Ap star population. With the potential to provide far reaching impacts on stellar physics, an expansion of this population of pulsating star is a worthwhile endeavour. Here we propose to significantly increase the number of known roAp stars by an expected 40 members through TESS 2-min observations of stars newly classified as Ap using LAMOST spectra. This will provide the an unrivalled legacy sample of roAp stars for ensemble studies with which a broad spectrum of stellar physics can be explored.

Target List

TESS will obtain its first coverage of the nearby Ophiuchus star-forming region in April 2025. We target two young stars in the region which HST images have shown to be edge-on protoplanetary disks: bipolar reflection nebulae separated by a dark lane (the disk), and with diameters of 2-3 arcsec. Both have approved imaging observations with JWST. K2 data for the first target shows a factor of two variation in brightness with an ~8 day period, while the second target has never been monitored before. We reguest 2 min cadence of observations of both targets during Sector 91. The results will test the hypothesis that stellar accretion hotspots are the source of the observed beaming in the disk reflected light, by observing one edge-on disk with strong accretion sigantures and one without.

Target List

A tidal disruption event (TDE) occurs when a star is ripped apart by a supermassive black hole (SMBH). Many TDE models are sensitive to the early-time emission, a phase that is currently poorly constrained. We propose to use the high cadence and high precision photometry of TESS to probe the early phases of TDEs, which encode information on the disrupted star and SMBH. Strong constraints on TDE rise times and slopes will inform theoretical models on how the first light from TDEs is produced. These parameters may also connect to the environment surrounding the SMBH. TESS will also place deep limits on pre-existing AGN activity in TDE host galaxies. We expect TESS to detect at least 1-2 new TDEs in Cycle 7 as well as 10 additional TDEs with pre-flare TESS observations of their host galaxy.

Target List

Cycle 7 presents the opportunity for TESS to re-observe 158 bright pulsating white dwarfs, and to observe 7 known and 77 likely pulsating white dwarfs for the first time. Rapid pulsations of white dwarf stars require 20-s cadence to ensure coverage below the Nyquist frequency. We aim to secure these essential data for white dwarf asteroseismology. New pulsation periods will add valuable new constraints on white dwarf interior structures. With Cycle 7 data, we will characterize the evolution of pulsation signals from space on timescales of up to 7 years, and we will detect new pulsational outbursts. We will publish the definitive catalog of white dwarf pulsation periods and mode characteristics as seen by TESS, which is expected to serve as a key reference for future asteroseismic studies.

Target List

M-dwarfs host the most number of Earth-like exoplanets in their habitable zones. But, their high flaring rates can potentially destabilize nearby planets. So, it is essential to monitor dMs for flares and study their evolution and space-weather impacts. To explore the space weather relevance of the flaring events, it is hence important to understand the cross-atmospheric evolution of these photospheric flares into the upper chromospheric layers. This requires simultaneous wideband monitoring studies. In this proposal, we request high cadence TESS 20-second data for EV Lacertae, for Sectors 84 at the start of Cycle 7, in October 2024. We will submit a separate DDT for Cycle 6, Sector 83 data if we obtain radio time.

Target List

We propose 2-min cadence observations of 6947 young stars located in 55 nearby associations, co-moving groups and open clusters with ages spanning 1 Myr - 3 Gyr. Young planets can constrain key processes that drive the early evolution of planetary systems and inform our understanding of various properties observed in the older exoplanet population. Stellar activity plays an important role in this evolution, especially at young ages. We will search for young transiting planets and characterise the early evolution of stellar flare activity to understand the subsequent diversity and habitability of planetary systems. We additionally propose 20-sec cadence observations of 30 potentially young TOIs to facilitate detailed transit and flare analyses in these systems.

Target List

The formation mechanisms invoked to explain the existence of the multi-planet systems so ubiquitous in the exoplanet sample often involve disk migration, a mechanism which frequently results in capture into mean motion resonance (MMR). However, since we cannot observe the processes of disk migration directly, we are left studying its byproducts, which includes the orbital architectures of systems where planets are found near or in resonance. To make further progress towards understanding these fundamental formation questions, we propose to study transit timing variations (TTVs) of planets in multi-planet systems near or in resonance using TESS Cycle 7 observations. These new measurements of TTVs will extend existing baselines on our targets, resulting in more precise orbital solutions and

Target List

We propose conducting multi-color photometry of highly active bright G-M dwarf flare stars. We perform simultaneous high-time cadence observations (~20 sec) with both TESS and ground-based telescopes. Our approach involves the utilization of custom narrow-band filters attached to the Apache Point Observatory's 3.5m and 0.5m telescopes, and simultaneous Swift & NICER observations. Our aim is to create an unprecedented catalog of Balmer jump ratios and multi-color emission properties of TESS flares. We plan to investigate how these properties evolve during the flare time, and discuss the physical mechanisms that determine flare heating rates. Our study will enable us to more accurately estimate flare energy and provide a critical constraint for the flare emission effects on exoplanets.

Target List

Stellar companions and exoplanets in wide orbits are poorly understood, in particular around intermediate-mass stars for which spectroscopic radial velocities cannot be precisely measured. We propose to use pulsation timing variations to map orbits around the intermediate-mass delta Scuti variable stars, probing both exoplanets and binary companions. The method is immune to data gaps and increases in sensitivity with the orbital period and is thus ideally suited for the 7-year timebase that will be enabled through TESS Cycle 7.

Target List

Recent pebble accretion models have estimated that the occurrence of Earth/super-Earth planets (1-4 Rearth) peaks around stars with masses 50% the mass of the Sun, and decreases for smaller stars, citing TRAPPIST-1 and Teegarden's Star as rare systems. We propose 20-second and 2-minute cadence observations for a magnitude-limited (Tmag < 13) sample of stars with masses between 10%-30% the mass of the Sun, which will mitigate issues with pointing jitter in FFIs. We discuss that higher cadence observations of the brightest very-low-mass stars will add an additional 4-8 planets in Cycle 7, doubling the yield expected from FFI frames. This magnitude-limited sample, which was systematically built, will provide stronger constraints on the planet occurrence rate for the lowest-mass stars.

Target List

We request 20-second cadence data for 92 neutron stars accreting from low mass binary companions to search for thermonuclear bursts. These bursts start as X-ray flares of durations typically of about 10-100 seconds, and the X-rays then heat the outer parts of the accretion disks, and part of the X-ray emission is reprocessed into the optical band. The recurrence time of the bursts is set by the time it takes to accrete a pile that heats up enough to trigger CNO burning, and understanding the recurrence time as a function of accretion rate yields key information about nuclear physics. TESS's continuous coverage and wide field are necessary to estimate the recurrence times, which have been hard-to-impossible to measure over the 50 years in which these bursts have been observed to date.

Target List

We propose to operate an existing pipeline to provide calibrated target pixels, light curves, and full transit search results for more than 150,000 targets per sector selected from the TESS Cycle 7 200 second cadence FFIs. We will provide a machine learning (ML) vetted list of planet candidates from the transit search. Our analysis will also generate cotrending basis vectors useful for mitigating systematic errors in any light curves generated from the full frame image data. We will provide data products for over 2 million targets. Our transit search will uncover more than 50 thousand potential transit detections that will include hundreds of new exoplanet candidates. We will archive all resulting data products as High Level Science Products at the Mikulski Archive for Space Telescopes.

Target List

We propose to combine TESS photometry and ground-based spectroscopy to measure the fundamental parameters of 30 low-metallicity main sequence eclipsing binaries (EBs). Detached EBs are the most effective tool to measure precise masses and radii of stars. Less than half of main sequence binaries with dynamical masses and radii have metallicity estimates, and there are even fewer metal poor targets. We identified 42 metal poor EB candidates by combining the ASAS-SN EB catalog with spectroscopic surveys and Gaia astrometry. We propose to use TESS light curves and ground-based radial velocities to dynamically measure the masses and radii of 30 systems. By doing so we can improve models for metal poor stars and empirical relations between stellar properties.

Target List

Stellar oscillations offer a unique window into the internal dynamics of stars and have become the gold-standard for calibrating fundamental stellar properties. These observations trace the time variation of either intensity (through photometry) or radial velocity (though spectroscopy), but almost never with both. However, simultaneously monitoring oscillations using both channels can significantly improve our understanding of stellar interiors and atmospheres, offering constraints that differ from those obtained through either method alone. Here we propose a pioneering set of simultaneous observations of stellar oscillations in solar-type stars to address this critical gap, using TESS and ground-based Extremely Precise Radial Velocity instruments.

Target List

We propose to obtain a mix of 20-s cadence and 200-s FFIs for 972 binary systems likely to host detectable oscillations in both components, selected with Gaia. We will combine asteroseismic parameters nu max and delta nu extracted from these images with luminosities, distances, and temperatures to obtain asteroseismic masses. Combined with metallicities obtained from gaia-xgboost and spectroscopic follow-up, these masses complete the set of constraints needed to calibrate isochrones. Such calibration systems are rare: this campaign will yield a 5-fold increase in the number of ``holy grail'' targets whose components share an age but have two different masses. We will use Cycle 7 s timely overlap with K2 fields to benchmark our method for 20 targets observed in both K2 and TESS Cycle 7.

Target List

The discovery of closely-orbiting, eccentric planets by TESS has indicated that dynamical processes have a strong influence on the evolution of planetary system architectures. Such dynamical processes can lead to the engulfment of planets by their host stars, which is thought to be a mechanism by which lithium (Li) may be enhanced in these stars. Such engulfment-induced Li enhancement signatures have the strength and longevity to be detectable. We propose to conduct a comprehensive Li abundance survey of subgiant and early red-giant-branch stars which are known to host closely-orbiting, eccentric planets using high-resolution ground-based spectroscopy. Our survey will serve to constrain the link between dynamical interactions in planetary systems and engulfment events.

Target List

The Scorpius-Centaurus association (Sco-Cen) contains 90% of young, pre-main sequence stars near the Sun. The Upper Scorpius region of Sco-Cen is <20 Myr old and will be observed by TESS for the first time in Cycle 7. The goal of this proposal is to maximize the TESS science return from analyses of Sco-Cen. We will do this by combining new Cycle 7 observations with archival data to create new light curves. Our interest is in finding young transiting exoplanets, so we will proceed by developing methods for detecting transiting planets in spot-dominated light curves, producing the highest quality light curves possible, and searching those light curves for real planets. Our light curves, planet-search software, and planet catalog will all be made available to the community.

Target List

Stellar models and isochrones are calibrated to match the properties of Sun-like stars, but often struggle in other regimes (e.g. low-mass stars and evolved stars). Bright eclipsing binary (EB) systems are excellent test beds for stellar models, which must reproduce both stars' precisely measured physical properties at the same age and composition. We request TESS FFIs for 13 such EBs whose components are in different evolutionary stages (e.g. a dwarf and a giant) and thus provide stringent, HR-diagram-spanning tests. We will extract light curves from the FFIs; measure their masses, radii, and temperatures to high precision the eclipses, radial velocities, and spectral energy distributions; and compare to predicted values from several stellar models.

Target List

We propose ultrafast, 20-second-cadence observations of several hundred white dwarfs visible in Cycle 7 of the TESS mission. Our proposed 20-second observations are necessary to adequately sample the short-period photometric changes of known variable white dwarfs; the variability arises from surface spots rapidly rotating in and out of view, as well as pulsations, eclipses and transits. Our proposed science case requires the fastest cadence available from TESS, and will expand the largest catalog of rapid variability in white dwarfs ever created.

Target List

Leveraging TESS's ability to monitor low-occurrence planets around bright stars, we propose a comprehensive study of stellar obliquity across 35 warm giants, with a special focus on the less explored warm Jupiters near hot stars and warm Sub-Saturns. Our aim is to unravel the origins of their spin-orbit misalignments: whether they arise through high-e migration or broader universal processes and to analyze how these patterns evolve with stellar temperature. By comparing the spin-orbit alignments of warm Jupiters and Sub-Saturns, we seek to uncover the specific dynamical processes shaping their orbits. This endeavor is set to provide significant insights into the formation, evolution, and dynamic history of short-period gas giants, contributing to the broader question of our Solar System.

Target List

The work proposed here will use full-frame images (FFI) to investigate both temporal and spatial phenomena in comets that serendipitously pass through the TESS fields of view during years 6 and 7 of the mission. Temporal phenomena include long term secular changes in a comet s activity as it approaches or recedes from the Sun, periodic brightness variations that reflect the nucleus rotation, and rapid, sometimes massive, brightness increases produced by explosive outbursts that are seen in many comets. Spatial studies will focus on coma morphology and the search for dust trails comprised of large dust grains that contain most of the mass lost by the comet.

Target List

Convective boundary mixing (CBM) has far-reaching astrophysical consequences: it determines the lifetimes, final fates, physical properties, and population statistics of massive stars and compact objects, and governs the properties of standard candles like red clump stars. Despite this importance, it remains a major source of uncertainty in stellar modelling. Asteroseismology is our only means of probing its effects on stellar structure. Whereas existing asteroseismic investigations into CBM examine it above convective cores, we propose to use 200-second TESS full-frame images (FFIs) to probe CBM under convective envelopes, in late subgiants: a hitherto observationally inaccessible phase of evolution, and a physical regime in which it has so far been largely overlooked.

Target List

Despite large-scale efforts by the community, access to time-series photometry from the FFIs remains severely limited for stars with Tmag>13-14. To remedy this, we developed a user-friendly pipeline for extracting deblended PRF and optimized aperture photometry from FFIs. The proposed work will publish v1.0 of our pipeline after minor development, and improve the current pipeline further with an implementation of a dynamic, fully analytical PRF model (v2.0). The hyper-parameters for the PRF model will be computed and made available within 2 weeks of each sector's data release in Cycle 7. By reducing the barrier to light curve extraction, this work will allow users to access systematics-corrected and deblended light curves as soon as seconds after calibrated FFI data becomes available.

Target List

We propose to monitor the HST/CALSPEC database of photometric standard stars for significant variability using the TESS 2-minute data. This database calibrates astronomical images in the optical and infrared, including those taken by telescopes like Spitzer and the James Webb Space Telescope (JWST). TESS has already identified variability larger than 1% in a subset of these stars. These stars are necessary to accurately calibrate the absolute and relative flux across different instruments and observatories. By monitoring these targets with TESS, we will detect and constrain their variability, empowering observatories like JWST to efficiently choose stars that will produce the best possible spectrophotometric calibrations.

Target List

In contrast to main sequence systems, planet populations of evolved stars remain poorly understood. TESS has changed this by tripling the number of planets known transiting evolved stars. However, the vast majority of new discoveries have been high-SNR hot Jupiter systems, due to the relatively short TESS light curves available at first. Now, TESS Extended Mission data is making it possible to confirm longer-period and smaller-radius planets around evolved stars. Here, we propose to use the TESS Cycle 7 data to find additional transiting planet candidates around evolved stars that would otherwise be overlooked. We predict the detection of 5-10 new planet candidates, which will help resolve decades-old debates about planet inflation and migration at late evolutionary states.

Target List

Starspots and faculae are challenging to study due to observational degeneracies between spectral temperature and fractional coverage of the stellar surface, and the presence of these active regions is a hindrance to studies of transiting exoplanets as they affect the host star's spectrum and introduce false positive signatures of atmospheric absorption. To address this and help mitigate spot contamination in exoplanet transmission, we propose a study of rapidly rotating M Dwarfs observable both by TESS and ground-based facilities which we will use to understand the multi-color character of stellar rotation. The proposed study will yield measurements of spot temperature for a sample of stars which is representative of many of TESS' L1 transit hosts.

Target List

Most novae fade back to quiescence over weeks to decades. But there are exceptions, and it is these exception that provide us with important insights into the interactions of these close binary systems. The post novae V1280 Sco and V5856 Sgr are stuck some 7-9~mag brighter than their pre-outburst magnitudes. In this extended plateau the light curves feature dips during which the optical brightness drops by up to 1 mag. During these dips the spectra change from one dominated by cool lines to a hot spectrum with strong He II 4686 and Bowen N III lines, and forbidden [O III] and [Fe VII]. This suggests that the drop in continuum opacity is revealing the central ionizing source. We propose to use TESS and Swift, along with ground-based photometry and spectroscopy, to investigate these systems

Target List