Upcoming Events

The NICER AO4 proposal deadline is November 10, 2021 at 4:30 Eastern Time.

NICER Science Nuggets

Check out the most recent NICER Science Nugget
reporting ongoing X-ray science being performed
on board the International Space Station.

Latest News

  • Joint NICER/IXPE Analysis Workshop (01 May 2024)
    The 2024 Joint NICER/IXPE Workshop will be held at The George Washington University in Washington D.C from Monday, 29th of July, 2024 to Thursday, 1st of August, 2024. Registration is free for both in-person and remote attendees
  • Update to Enhanced Visibility Calculator (09 Feb 2024)
    The NICER enhanced visibility calculator, which provides detailed target visibility information taking into account blockages by ISS structures and other constraints, has been updated. This update allows calculation of target visibilities using orbit day target/sun angles greater than 90 degrees, appropriate for targets observed during ISS orbit day in the presence of the XTI light leak. The update also allows the user to calculate visibilities for observations restricted to orbit night or orbit day.
  • Update on Patching the NICER Light Leak (25 Jan 2024)
    On January 9, 2024, the NICER team received approval from the ISS program to proceed with a light-leak repair effort via either the ISS robotic system (EVR) or ISS astronauts during a spacewalk (EVA). The choice of EVR vs. EVA is expected to be made by the end of February. See the NICER Light-leak Update for more information.
  • NICER Cycle 6 Proposal Results Available (29 Nov 2023)
    The result of the recent NICER Cycle 6 review is now available for accepted proposals and approved targets. Cycle 6 begins March 1, 2024. The deadline for Cycle 6 Phase 2 proposals for accepted programs is January 24, 2024.
  • Important Bug Fix to NICERDAS 11 (24 Aug 2023)
    There's a significant bug in the version of nifpmsel released in HEASoft 6.32/NICERDAS 11, which can cause an incorrect normalization of lightcurves and spectra in some cases. NICERDAS users should update to HEASoft 6.32.1 and afterwards use nicerl2 to reprocess any NICER data processed with HEASoft 6.32/NICERDAS 11. A patch installer script is available to update existing HEASoft 6.32 installations to HEASoft 6.32.1.
  • HEASoft 6.32/NICERDAS 11 released (20 Jul 2023)
    HEASoft 6.32 was released on July 20, 2023. This release includes NICERDAS 11, a moderately significant feature release for NICER which contains a number of improvements, especially to deal with the optical light leak which developed on May 22, 2023. Please see the HEASoft 6.32 release notes for details.
  • Increase in NICER Daytime Light Loading (06 Jun 2023)
    On May 22, 2023, between 13:00 and 14:00 UTC, NICER appears to have developed an increase in optical contamination during daytime observations. The cause of this increase, and mitigation strategies are being evaluated. Observations during orbit night seem mostly unaffected. For details, please see the NICER "Tips and Caveats" page.
  • Spurious Timing Signal for NICER MPU 1 and 3 (22 Feb 2023)
    Since (at least) the start of 2023, low-sun angle data sets show non-science-related (spurious) power in a narrow band at 55 Hz, and a broad feature in the 18-30 Hz range. This timing feature is seen only on MPUs 1 & 3 (zero indexed), approximately identical for both MPUs and independent of energy. The NICER team is currently investigating the cause of this signal, and any remedies. Users should exercise caution in interpreting signals near these frequencies.
  • NICER Cycle 5 Accepted Proposals and Targets Now Available (24 Dec 2022)
    The NICER mission is pleased to announce that the proposal selection process for Cycle 5 of the Guest Observer program is complete, with observations scheduled to begin no later than March 1, 2023. Documents listing selected proposals and approved targets have been posted to the HEASARC's NICER Proposals Page.
  • NICER XTI CALDB Updated (31 Oct 2022)
    The NICER XTI caldb has been updated to version 20221001. This version updates the detector gain, response and includes new background files.
  • OHMAN Monitoring Service Has Started (25 Oct 2022)
    The "OHMAN" (Orbiting High-energy Monitor Alert Network) X-ray follow-up observation program began operation on August 10, 2022. OHMAN uses JAXA's MAXI all-sky monitor to detect sudden X-ray bursts and to automatically notify NASA's NICER sensitive X-ray telescope for immediate followup. The first coordinated observation was successfully completed on September 13, 2022.
  • 2022 NICER Proposal and Science Workshop, Aug 31-Sep 1 (28 Jul 2022)
    In anticipation of the Cycle 5 proposal deadline (Sep 14, 2022). the NICER project will hold a Proposal and Science workshop highlighting the technical and scientific capabilities and strength of the NICER mission. The workshop will be held virtually on August 31st and September 1st, 09:00-11:00 and 14:00-16:00 EDT. Registration is free.
  • NICERDAS 9 Released (28 Apr 2022)
    NICERDAS version 9, distributed in HEASoft 6.30, includes some NICER-related changes to nicerl2, niprefilter2, nicerarf. Please see the NICERDAS 9 page for details.
  • NICER Cycle 4 Budget Proposals Due May 4, 2022 (04 Apr 2022)
    The Phase 2 budget proposal deadline for accepted NICER Cycle 4 proposals with recommended observations of Category A or B targets is May 4, 2022 at 4:30pm EDT.
  • Keith Gendreau, Zaven Arzoumanian and the NICER Team win the 2022 Rossi Prize (18 Mar 2022)
    The 2022 Bruno Rossi Prize has been awarded to Keith Gendreau, Zaven Arzoumanian and the NICER team "for development of the Neutron Star Interior Composition Explorer (NICER) and the revolutionary insights it is providing about the extreme environments of neutron stars and black holes, including the first precise and reliable measurement of a pulsar's mass and radius from detailed modeling of its pulsed waveform."
  • NICER Cycle 4 Proposal Results (23 Feb 2022)
    The result of the recent NICER Cycle 4 review is now available for accepted proposals and accepted targets. Cycle 4 begins March 1, 2022. Note that observations after Sept. 30, 2022 are contingent on Senior Review mission continuation. Also note that the deadline for Cycle 5 proposals (September 7, 2022) is earlier than for previous cycles.
  • Solication for Proposals for NICER Cycle 5 Released (14 Feb 2022)
    The solicitation for observations in the NICER cycle 5 observing interval (Mar 2023 - Feb 2024) has been released.
  • The NICER Enhanced Visibility Calculator Released (05 Oct 2021)
    The NICER Enhanced Visibility Calculator calculates NICER visibilities for targets over roughly the next 2-week period taking into account ISS orientation and target occultation by ISS structures, and other relevant constraints. These visibility intervals are more accurate than visibilities based solely on Sun and Moon avoidance
  • NICER XTI CALDB Updated (20 Jul 2021)
    The NICER XTI caldb has been updated to version 20210707. This version updates the detector gain, response and effective area of the XTI and other files.
  • NICER detection of possibly periodic X-ray absorption dips in MAXI J1803-298 (06 May 2021)
    New NICER observations of the X-ray transient MAXI J1803-298 shows recurrent absorption dips in the lightcurve similar to dips seen in other high-inclination X-ray binaries, and suggest a possible orbital period of 7-8 hours.
  • NICER follow-up observations of MAXI J1803-298 (05 May 2021)
    Continuing NICER observations of the new X-ray transient MAXI J1803-298 show temporal and spectral properties suggestive of a hard state accreting stellar-mass black hole than a neutron star, though confirmation is still needed.
  • NICER detection of periodicity in the new X-ray transient MAXI J0901-531 (19 Apr 2021)
    NICER observation of the newly-discovered X-ray transient MAXI J0901-531 found periodic X-ray variations with a period of P = 14.055 seconds, consistent with the gamma-ray period seen by Fermi.
  • NICER Finds X-ray Boosts in the Crab Pulsar's Radio Bursts (08 Apr 2021)
    A global science collaboration using data from NASA's Neutron star Interior Composition Explorer (NICER) telescope has discovered X-ray surges accompanying radio bursts from the pulsar in the Crab Nebula. The finding shows that these giant radio pulses release far more energy than previously suspected.
  • NICER follow-up of SRGA J181414.6-225604 (08 Apr 2021)
    NICER followup observations of a possible new X-ray transient discovered by the SRG observatory detected a source showing a peak in soft X-rays and a hard non-thermal tail at higher energies. No evidence for temporal variability was seen.
  • NICER Virtual Data Analysis and Science Meeting: Registration Open (31 Mar 2021)
    Registration is now open for a virtual data analysis workshop, which will be held the week of May 10, 2021, on Monday, Tuesday, Thursday and Friday, 9 am to 1 pm. You can register using the workshop registration form.
  • NICER and Swift observations of the new outburst of MAXI J1820+070 (30 Mar 2021)
    NICER and Swift observations of the black hole X-ray transient MAXI J1820+070 near the start of its outburst found an X-ray luminosity of only 1e33 ergs/s. This is one of the lowest luminosities at which the start of a black hole-X-ray transient outburst has been caught in X-rays.
  • NICER X-ray activity shows GX 339-4 undergoing a rapid state transition (28 Mar 2021)
    NICER observations of the black hole binary system GX 339-4 during its recent outburst shows the presence of an evolving QPO in the power spectrum indicating that the source entered a hard-to-soft state transition.
  • Rounding off PSR J0537-6910 with NICER and LIGO (15 Mar 2021)
    PSR J0537-6910 is fastest-rotating young pulsar known, monitored by NICER since 2017. It is losing energy faster than any other known young pulsar, which could be due to the emission of gravitational radiation. However, LIGO, Virgo and KAGRA gravitational wave detectors failed to detect the source. This shows that some other process is responsible for slowing the pulsar down, and that the neutron star must be spherical to better than 1 part in 30,000.
  • NICER follow-up of the Be X-ray pulsar Swift J1626.6-5156 (14 Mar 2021)
    NICER observations of the recent X-ray outburst from the Be X-ray binary Swift J1626.6-5156 showed strongly pulsed emission with a 15.34 second period with the possible detection of a cyclotron absorption line similar to a feature seen previously.
  • NICER follow up of the new X-ray transient IGR J17533-2928 (08 Mar 2021)
    NICER observations of the new transient IGR J17533-2928 about a week after it was first detected by INTEGRAL showed that the spectrum was consistent with modified blackbody emission and did not detect any pulsed emission. The nature of the transient remains to be revealed.
  • NICER Spectroscopy of MAXI J1848-015 in the Stellar Cluster GLIMPSE-C01 (02 Mar 2021)
    NICER observations of this new transient show complex iron line emission and a luminosity much less than the typical Eddington luminosity for a neutron star.
  • NICER detects pulsations from Swift J1749.4-2807 (02 Mar 2021)
    NICER observations of the eclipsing, accreting millisecond pulsar Swift J1749.4-2807 finds a 1-10 keV X-ray luminosity of 2E36 ergs/s and recovers the the 518 Hz pulsation period.
  • Resumed NICER observations of the magnetar SGR 1830-0645 (19 Feb 2021)
    NICER has resumed observation of the magnetar SGR 1830-064 since it emerged from sun constraint on February 10. NICER shows that the source flux decay has flattened compared to values early in the outburst.
  • NICER Cycle 3 Accepted Proposals (10 Feb 2021)
    The NICER mission is pleased to announce that the proposal selection process for GO Cycle 3 is complete, and observations will begin March 1, 2020.
  • NICER X-ray activity indicates GX 339-4 rising in hard state (10 Feb 2021)
    NICER observations of GX 339-4 during its current outburst, indicates that this low-mass X-ray binary is entering a canonical hard state, and is already twice as bright as it was in the previous two hard-only outbursts.
  • Jocelyn Bell Burnell Awarded the 2021 Gold Medal by the RAS (22 Jan 2021)
    The Royal Astronomical Society has awarded its highest honor, the Gold Medal, to Professor Dame Jocelyn Bell Burnell of the University of Oxford, the discoverer of radio pulsars, for her many contributions to astronomy.
  • Swift and NICER Show that the X-ray Outburst of Cen X-4 has Ended (13 Jan 2021)
    Observations with NICER and Swift, along with ground-based observations, suggest that the Cen X-4 has returned to quiescence
  • Swift and NICER Indicate a Rare X-ray Outburst of Cen X-4 (06 Jan 2021)
    Following indications from ground-based observations, X-ray observations by Swift and NICER show a sudden X-ray brightening of the nearby low-mass X-ray binary Cen X-4, suggesting the onset of a rare X-ray outburst
  • NICER Resumes Science Observations (04 Jan 2021)
    NICER science operations, interrupted because of power issues on the ISS, resumed on Dec 23, 2020
  • NICER Interruption of Science Observations (16 Dec 2020)
    An unforeseen power condition onboard the International Space Station has required that NICER cease science operations and remain safely stowed for a few days. Look for further updates on the NICER home page
  • NICER observes a New Tidal Disruption Event (07 Dec 2020)
    A new transient source discovered by Gaia on 21 April 2020 has been attributed to a star in the process of being swallowed by a supermasive black hole at the center of a galaxy. NICER observations of the source indicates that the X-ray emission from the source increased by a factor of about 26 in about 8 months.
  • NICER bkg_estimator v0p6 released (25 Nov 2020)
    A update to the NICER bkg_estimator software, v0p6, has been released. This version fixes a bug in estimation of background counts in the lightcurve generator method mk_bkg_lc_evt
  • NICER observations of 4FGL J0658.6+0636, candidate counterpart to the IceCube neutrino event IceCube-201114A (20 Nov 2020)
    NICER observed the Fermi gamma-ray source 4FGL J0658.6+0636, which may be the source of a high-energy neutrino detected by IceCube. The NICER unabsorbed flux was consistent with the enhanced flux detected in an earlier observation by the Swift XRT obtained 16 hours after the neutrino detection.
  • NICER and NuSTAR observations of the Be/X-ray binary pulsar 1A 0535+262 in outburst (17 Nov 2020)
    NICER and NuSTAR observations of the Be/X-ray binary pulsar 1A 0535+262 during its recent giant outburst reveal complex pulsations with a pulse period of 103.57s, while its spectrum shows fluorescence iron emission along with cyclotron features.
  • NICER Detects X-ray pulsations from IGR J17494-3030 (28 Oct 2020)
    NICER observations of the newly-active source IGR J17494-3030 have detected a 376-Hz X-ray pulsation modulated but a 4509s period, showing that this source is an ultracompact binary with an accreting neutron star and a companion with a minimum mass of 0.015 solar masses.
  • NICER identifies SGR 1830-0645 as a Magnetar (22 Oct 2020)
    NICER observations clearly show that the recently discovered source SGR 1830-0645 is a magnetar with a magnetic field strength of about 3x1014 gauss.
  • NICER and NuSTAR observations of the Blazar BL Lac (15 Oct 2020)
    NICER and NuSTAR obtained director's discretionary observations of the blazar BL Lac after its historical optical-to-gamma ray maximum. The NICER & NuSTAR spectrum can be fit with a broken power law, and these observations confirm the active state of the source.
  • NICER detects pulsations from a new outburst of the accreting millisecond X-ray pulsar IGR J17379-3747 (01 Oct 2020)
    New NICER observations of the re-activated accreting pulsar IGR J17379-3747 recovered the 468 Hz spin period of the pulsar and made a new measurement of the change in the orbital period.
  • X-ray flaring of the nuclear transient AT2019avd (23 Sep 2020)
    Swift and NICER observations of the galactic nuclear transient discovered by the Zwicky Transient Facility shows that the source X-ray brightness increased 1000-fold over the last 5 years and show unusual X-ray properties.
  • X-ray Brightening of AT2019wey (10 Aug 2020)
    NICER and Swift have obtained X-ray observations of AT2019wey, a new transient discovered by Spektr-RG. Both NICER and Swift show continued increasing emission through August 9 from this putative accreting binary.
  • NICER XTI CALDB Updated (27 Jul 2020)
    The NICER XTI caldb has been updated to version 20200722. This version updates the detector gain, response and effective area of the XTI.
  • NICER X-ray observations of the Tidal Disruption Event (TDE) candidate AT2020ocn (13 Jul 2020)
    NICER has been monitoring the X-ray evolution of the likely TDE event, AT2020ocn.
  • NICER detection of pulsations from RX J0529.8-6556 (23 Jun 2020)
    After the SRG/eROSITA discovery of a strong outburst from the LMC Be/X-ray binary RX J0529.8-6556, NICER followup observations discovered a period of 68s, indicating that the pulsar has been spinning up over the last 20 years.
  • Version 0p5 of the NICER Space Weather Background Tool Released (22 Jun 2020)
    Version v0p5 of the nicer_bkg_estimator software has been released. This version fixes an issue with the calculation of the deadtime correction and also updates the EXPOSURE time keyword in the primary and GTI extension headers
  • NICER observes the tail of a long-duration X-ray burst in the direction of MAXI J0911-655 (26 May 2020)
    NICER observations in the region including the intermittent accreting millisecond X-ray pulsar MAXI J0911-655 show a decrease in temperature consistent with the cooling tail of a thermonuclear X-ray burst from the neutron star.
  • NICER observations of GRO J1008-57 (21 May 2020)
    NICER has observed X-ray emission from the Be/X-ray binary system GRO J1008-57 during its current outburst. NICER finds a pulsation period of 93.205 with a spin period consistent with that measured at higher energies by the Fermi/GBM instrument. The spectrum is consistent with comptonized emission from an accretion disk with plus a blackbody, along with partial-covering absorption.
  • X-ray monitoring of the active magnetar SGR 1935+2154 (12 May 2020)
    NuSTAR, Swift and NICER are monitoring the current X-ray outburst of the soft gamma-ray repeater, SGR 1935+2154
  • Burst forest from SGR 1935+2154 as detected with NICER (28 Apr 2020)
    NICER observed the bursting magnetar SGR 1935+2154 in a series of observations. The NICER lightcurve shows over 100 bursts within a 1 kilosec observation.
  • NICER sees the Shortest X-ray Recovery of Eta Carinae (15 Apr 2020)
    NICER observations of the last X-ray minimum of Eta Car show that it began on Feb 13, 2020, and ended on March 15, 2020. This X-ray minimum is now the shortest on record.
  • NICER follow-up observation and a candidate timing anomaly from Swift J1818.0-1607 (25 Mar 2020)
    NICER followup observations of the magnetar candidate Swift J1818.0-1607 imply a spin down age of 310 years based on the period derivative. This makes Swift J1818.0-1607 one of the youngest magnetars known.
  • NICER and NuSTAR detections of Type I bursts and periodic dips in Swift J1858.6-0814 (18 Mar 2020)
    Observations of the low-mass X-ray binary Swift J1858.6-0814 by NuSTAR and NICER detected three thermonuclear "Type I" X-ray bursts, which strongly suggest that the compact object in Swift J1858.6-0814 is a neutron star. NICER observations also show deep, prolonged dips with a period of roughly 78640 s which may be due to the eclipse of the compact object by the companion star.
  • NICER detection of 1.36 sec periodicity from a new magnetar, Swift J1818.0-1607 (13 Mar 2020)
    NICER observations of a new soft gamma-ray repeater (SGR) candidate, Swift J1818.0-1607, revealed the presence of a 1.36 second period in the X-ray emission. This period suggests that Swift J1818.0-1607 is a new magnetar. If so, this source would have the shortest period of any known magnetar.
  • NICER Helps Usher the Golden Age of Neutron Star Research (04 Mar 2020)
    A new Nature article describes how researchers are getting closer to solving the enigmatic nature of neutron stars, in part thanks to the Neutron Star Interior Composition Explorer (NICER)
  • NICER Cycle 2 Accepted Proposals (03 Mar 2020)
    The NICER mission has released the list of accepted Cycle 2 proposals, along with a list of accepted targets with approved coordinated NuSTAR time. Cycle 2 observations began on March 1, 2020.
  • X-ray and near-infrared observation of rebrightening of MAXI J1348-630 (03 Mar 2020)
    New NICER observations of this black hole binary candidate confirmed the re-brightening of the system seen by MAXI in November and show the source to be in a hard state, possibly indicating the presence of a jet.
  • NICER detection of flux increase and spectral state change in Swift 1858.6-0814 (02 Mar 2020)
    Recent NICER observations of the low-mass X-ray binary Swift J1858.6-0814 show that the system is in an unusual state, in which the soft X-ray flux has increase by about a factor of 30 over the previous quiescent level, with little variability in the NICER observations.
  • NICER Observations of the 2020 X-ray Minimum of eta Carinae (24 Feb 2020)
    NICER has observed the 2020 X-ray minimum of eta Carinae, a long-period eccentric binary system which produces X-ray emission from the collision of the powerful stellar winds from the two stars. X-ray monitoring observations with NICER showed that the X-ray minimum began on 2020-02-13, at which time the observed X-ray flux dropped by about two orders of magnitude from the peak flux seem about 1 month earlier. The NICER observations help establish variations in the stellar wind mass loss and provide a probe of the dense inner wind of the Luminous Blue Variable primary star.
  • Re-brightening and decaying of MAXI J1348-630 as observed with NICER (11 Feb 2020)
    NICER observations of a new black hole candidate MAXI J1348-630 from Feb. 7 to 10 showed the source declining in X-ray flux by about a factor of 2 during this interval. NICER spectra show that the source is currently in the hard state. NICER will continue monitoring the source about once per day until the outburst fades.
  • Initial NICER observations of the mysterious source Swift J0840.7-3516 (aka GRB 200205A) and detection of short X-ray flaring activity (07 Feb 2020)
    The source Swift J0840.7-3516 was originally reported as a Gamma-ray burst sourcce by the Swift BAT on February 5. Followup observations by the Swift XRT showed X-ray emission that was inconsistent with a GRB, along with the possible detection of an 8.96 seconds. Followup X-ray observations with NICER showed X-ray flaring during which the X-ray flux increasd by a factor of 4, but did not confirm the X-ray period.
  • NICER observes a new outburst of V4641 Sgr (04 Feb 2020)
    V4641 Sgr is a binary system that contains a 6.4 solar mass black hole which went into X-ray outburst in early January. Observations by NICER on January 31 provided the best measure of the 2-10 keV spectrum and showed an inner disk radius temperature of about 1.5 keV, with no visible features in the power spectrum in the short NICER observation.
  • NICER sees a state change in MAXI J0637-430 (30 Jan 2020)
    NICER observations of the newly-discovered X-ray transient MAXI J0637-430 indicate that the source is a black hole X-ray binary system. Recent observations detail the decline of the soft, thermal X-ray emission from the source which entered a hard state on January 14, 2020, indicating a signficant change in the accretion disk around the black hole.
  • NASA's NICER Delivers Best-ever Pulsar Measurements, 1st Surface Map (12 Dec 2019)
    Astrophysicists have redrawn the textbook image of pulsars thanks to new detailed monitoring by NICER of the X-ray pulsar J0030+0451. NICER's detailed measurement of the X-ray pulse shape allowed the distribution of X-ray hot spots over the surface of the pulsar to be mapped out, and determined precise values for the size and mass of the pulsar. A series of papers analyzing NICER's observations of J0030 appears in a focus issue of The Astrophysical Journal Letters.
  • An X-ray Flare from eta Carinae as seen by NICER (03 Dec 2019)
    NICER monitoring of the massive colliding wind binary eta Carinae as the stars approach periastron passage has detected a sudden X-ray brightening. This X-ray flare is similar to the X-ray flaring seen at a similar orbital phase in previous binary orbital cycles. X-ray flaring should continue until the star reaches it X-ray maximum before the decline to the X-ray minimum on 2020 February 13.
  • NICER detection of 9.29 s pulsations from RX J0209.6-7427 (25 Nov 2019)
    NICER observations of the hard X-ray transient MAXI J0206-749 = HMXB RX J0209.6-7427 revealed a strong 9.29 s X-ray periodicity, making this system only the second confirmed pulsar in the Magellanic Cloud bridge.
  • NICER detection of a strong X-ray flare from GRS 1915+105 (25 Nov 2019)
    NICER detected a strong flare from the black hole binary system GRS 1915+105 during the source's current low flux state. The NICER flare was the largest yet seen from this system. This X-ray flare may have been the precursor to a strong radio flare seen from the source a short time after the NICER observation.
  • NASA's NICER Catches Record-setting X-ray Burst (07 Nov 2019)
    NICER detected an intense burst of X-rays at about 10:04 p.m. EDT on Aug. 20 from a massive thermonuclear flash on the surface of the pulsar SAX J1808.4-3658. This is the brightest burst seen by NICER so far. The burst shows a remarkable two-stage evolution in flux, along with and burst oscillations at the known pulsar spin frequency.
  • NICER Background Estimator Tools (30 Oct 2019)
    Software tools to estimate background in NICER observations are under development, based on analysis of deep NICER exposures of "blank-sky" fields. "Alpha-release" versions of these tools are now available to help NICER observers better estimate backgound in observations and proposals. Understanding of the NICER background is still evolving so the estimates provided by these new tools should be used with caution.
  • NICER detection of two thermonuclear (Type I) X-ray bursts establishes that MAXI J1807+132 hosts a neutron star. (29 Oct 2019)
    NICER has detected two thermonuclear X-ray bursts from the new MAXI X-ray transient MAXI J1807+132, discovered in March 2019. The detection of these bursts show that the system is an LMXB with a neutron star primary.
  • NICER Observes X-ray Brightening of a Tidal Disruption Event Candidate (23 Oct 2019)
    NICER observations reveal that the tidal disruption candidate source AT2019azh showed a late-time brightening which perhaps indicates the formation of a transient accretion debris disk around the supermassive black hole.
  • NICER is Back in Operation (21 Oct 2019)
    NICER is operating normally after stowing for last week's ISS operations.
  • NICER Stowed Due to ISS Operations (15 Oct 2019)
    In support of ISS operations, NICER has been stowed since Sunday, October 13. As a result, NICER is not currently taking requests for Target of Opportunity observations. We anticipate that NICER observations will resume as soon as the ISS operations are completed.
  • NICER observations of the X-ray transient MAXI J1807+132: flaring activity (08 Oct 2019)
    NICER has been monitoring the X-ray transient MAXI J1807+132 regularly since September 16. During this time, NICER detected brief, sudden episodes of X-ray brightening which may be analogous to similar flaring behavior seen near the end of the 2017 outburst of the source.
  • NICER observes increasing luminosity from XTE J1739-285 (30 Sep 2019)
    From September 27 to September 30, NICER observed this newly active Galactic Center high-energy transient. The NICER observations show that the X-ray flux in the 0.1-10 keV band more than doubled over a timespan of about 3 days, with a coincident increase in black body temperature.
  • NICER observations of the X-ray transient MAXI J1807+132 (27 Sep 2019)
    NICER observations of the new X-ray transient MAXI J1807+132, discovered on September 10. The NICER observations show large variations from 200 NICER counts per second to 14 counts per second within a week. The nature of this source, based on this initial analysis (and on obsevations in other wavebands), is uncertain, and additional observations are planned.
  • NICER follows up the rapidly variable and rising nuclear transient AT2019pevr (27 Sep 2019)
    NICER observation of this unusual source on 2019 September 25 found a 0.3-2 keV X-ray flux that is nearly 10 times brighter than the X-ray flux measured by Swift/XRT just one day earlier and about 100 times brighter than the archival ROSAT detection.
  • NICER detection of a 83 s periodicity in the super-soft source emission from V3890 Sgr (09 Sep 2019)
    Following the detection of super-soft source (SSS) emission from the recurrent nova V3890 Sgr by the Swift-XRT (Page et al., ATel#13084), NICER observations reveal a clear oscillation on a timescale of 83 s. The origin of this short-period modulation is possibly related to the spin of the white dwarf, or nonradial pulsations driven by an instability in the nuclear burning rate of the hot white dwarf.
  • NICER detects a high luminosity reflare from SAX J1808.4-3658 (04 Sep 2019)
    NICER monitoring of the accreting millisecond X-ray pulsar SAX J1808.4-3658 showed an unusually bright, abrupt and soft reflare from SAX J1808.4-3658 on 2019 Sep 3, during which, over the span of 5.7 hours, the observed count-rate increased fivefold. A 401 Hz QPO was also detected during this reflare. This suggests that the accretion disk has suddenly become smaller in radius.
  • NICER detects X-ray pulsations from the rapidly brightening SAX J1808.4-3658 (08 Aug 2019)
    NICER monitoring of the accreting millisecond X-ray pulsar SAX J1808.4-3658 successfully recovered a 401 Hz pulsation after correcting for delays due to the known binary orbit. The time of ascending node derived from the timing solution is 27 seconds earlier than predicted, which indicates that the orbital expansion is proceeding more slowly than expected.
  • NICER detection of QPOs from EXO 1846-031 (01 Aug 2019)
    Following reports of renewed activity from the X-ray transient EXO 1846-031, NICER executed rapid follow-up observations. These observations detected a sharp QPO at 0.26 Hz. The timing and X-ray spectrum suggest that this source is a black hole X-ray binary in the hard state.
  • GSFC X-ray Technology Opens New Frontiers in Space and on Earth (24 Jul 2019)
    The Miniaturized High-Speed Modulated X-ray Source (MXS) has been chosen as NASA's 2019 Government Invention of the Year. MXS was developed by Keith Gendreau (the NICER Project Scientist) and Zaven Arzoumanian (the NICER Deputy Project Scientist) and was used in the ground calibration of NICER. It also can help generate medical images similar to a CT scan for patients on earth and for astronauts in space.
  • Ultra-luminous X-ray pulsar NGC 300 ULX1 experienced unprecedented spin evolution, study finds (31 May 2019)
    NASA's NICER image shows 22 months of X-ray data recorded by the Space Station payload during its nighttime moves between targets.
  • NASA's NICER Shows Entire Sky in X-rays in Stunning Arc Image (31 May 2019)
    NASA's NICER image shows 22 months of X-ray data recorded by the Space Station payload during its nighttime moves between targets.
  • NASA Navigation Tech Highlights X-ray Navigation Using Pulsars (30 May 2019)
    X-ray navigation is a technology that NASA has already demonstrated on the International Space Station. X-ray navigation uses the ultra-regular oscillations of distant pulsars, a type of neutron star, for timing and location data.
  • NICER sees the contraction of the corona in a black hole X-ray transient (14 Jan 2019)
    NICER made the cover of Nature with an analysis by Kara et al. of the temporal behavior of the X-ray spectrum of the black hole transient system MAXI J1820+070. Their analysis of the time-resolved NICER spectra of this system showed that the inner edge of the accretion disk is near the accreting black hole and that variations in the X-ray spectral lags indicated that the corona shrank over a time interval of a few weeks.
  • NICERDAS Version 5 released (24 Oct 2018)
    The NICER data reduction software Version 5 was released on Oct 23 2018 with the release of HEASoft 6.25 . NICERDAS 5.0 includes updates to most tasks and includes new task, nicertimeconv, to do basic time conversions.
  • IGR J17591-2342 second re-brightening observed with NICER (21 Sep 2018)
    NICER observations of the second re-brightening of the accreting millisecond pulsar IGR J17591-2342 show it reaching its highest flux yet seen, with strong pulsations remaining after almost 60 days post-outburst.
  • NICER Guest Observer Program approved by NASA (07 Sep 2018)
    NASA has approved a Guest Observer program for NICER. We expect that the Announcement of Opportunity will be released this fall, with proposals due by the end of the calendar year. More information will be posted on the NICER home page when available.
  • NICER and NuSTAR Identification of X-ray Transient IGR J17591-2342 (17 Aug 2018)
    Observations by NICER and NuSTAR of the X-ray transient IGR J17591-2342 discovered by INTEGRAL on August 12 show that the new transient is an accreting millisecond pulsar in outburst. The pulsar has a spin frequency of approximately 527 Hz and an orbital period of 0.37 days.
  • A Rapidly Spinning Black Hole with a Warped Disk (17 Jul 2018)
    NICER provides a detailed look at a rapidly-spinning black hole feeding off its companion star.
  • NASA's NICER Mission Finds an X-ray Pulsar in a Record-fast Orbit (11 May 2018)
    Scientists analyzing the first data from the Neutron star Interior Composition Explorer (NICER) mission have found two stars that revolve around each other every 38 minutes. The discovery bestows the stellar pair with the record for the shortest-known orbital period for a certain class of pulsar binary system.
  • NICER in the News: NASA Will Solve a Massive Physics Mystery This Summer (01 May 2018)
    A LIVESCIENCE article about how NICER will determine the state of matter inside neutron stars.
  • NICER in the News: Mushroom Clouds on Neutron Stars (23 Apr 2018)
    NICER was featured in an on-line publication by LiveScience on the ability to study photospheric radius expansion bursts, or "mushroom clouds" occurring on neutron stars.
  • NICER XTI CALDB Updated to Version 20180417 (18 Apr 2018)
    The NICER XTI caldb has been updated to version 20180417. Please make sure you're using the most recent version of the caldb.config file in order to access the NICER XTI CALDB data.
  • NICER Session at the American Physical Society Meeting (17 Apr 2018)
    A special session featuring NICER first results was held at the April 2018 meeting of the American Physical Society. Two results, "Scientists Spot the Shadow of a Strange Wind Blowing Past a Black Hole" and "NASA's Got a Plan for a 'Galactic Positioning System' to Save Astronauts Lost in Space", were featured stories on LIVESCIENCE.
  • NICER ATEL: NICER observations of MAXI J1820+070 suggest a rapidly-brightening black hole X-ray binary in the hard state (15 Mar 2018)
    NICER observed the new X-ray transient MAXI J1820+070. The light curve shows large amplitude flaring on a time-scale of minutes. The X-ray spectrum shows a hard power-law spectrum and a low temperature disk blackbody component, while timing analysis shows a large amplitude broadband power spectrum. These characteristics strongly suggest that the source is a black hole X-ray binary that is rapidly increasing in flux through the canonical hard state.
  • NICER Archive Opens (08 Mar 2018)
    NICER was launched to the International Space Station on June 3, 2017, and began regular observations of celestial sources on July 17, upon completion of its commissioning activities. While observations to fulfill the mission's baseline science are ongoing, most data acquired to date -- during an initial validation period lasting nearly 8 months -- are now available in the public archive at the HEASARC. The archive includes over 3000 observations that have been processed with the latest instrument calibration products and software, also now released, and are accessible through the HEASARC's archive interfaces. Excluded are datasets for a few targets, to be released at a later date after evaluation of long-term calibration stability. Following this initial release, new observations will be delivered to the archive regularly after a two-week processing and validation period.
  • NICER XTI CALDB Updated (05 Mar 2018)
    The NICER XTI caldb has been updated to version 20180226. Please make sure you're using the most recent version of the caldb.config file in order to access the NICER XTI CALDB data.
  • NICER/SEXTANT proves pulsars can function as a celestial GPS (12 Jan 2018)
    "NASA test proves pulsars can function as a celestial GPS", published in Nature, discusses how NICER/SEXTANT for the first time demonstrated in-space navigation using X-ray pulsars as a form of a Galactic Positioning System. This method will help spacecraft autonomously steer themselves through deep space. These results were featured in a press conference at the 231st Meeting of the AAS, in Washington DC.
  • NICER overview published in Nature Astronomy (01 Dec 2017)
    "Searching for a pulse", an overview of NICER by K. Gendreau and Z. Arzoumanian, has been published by Nature Astronomy (Nature Astronomy 1, 895, 2017).
  • NICER ATEL: Observation of Fast X-ray Flares in GX 339-4 (06 Oct 2017)
    NICER observed the black hole binary GX339-4 which is currently in outburst. The average hard color (4-12 / 2-4 keV) is near 0.5 or higher, which is harder than the value for Crab (0.25). These results are consistent with the report that GX339-4 is in a faint black hole hard state (Gandhi et al., Atel 10820).
  • NICER First ATEL: The Hard X-ray transient MAXI J1535-571 (22 Sep 2017)
    NICER has observed the hard X-ray transient MAXI J1535-571 several times from 2017 September 9 through September 20. The source had a NICER count rate ranging from 3,200 to 17,000 counts per second over this interval. NICER detects a set of low-frequency QPOs in a 1:2 frequency ratio, while the time-averaged spectrum shows broadened iron emission and puts constraints on the black hole spin parameter and the inclination of the accretion disk.
  • NICER Featured on "Science in Seconds" (08 Sep 2017)
    NICER was featured on "Science in Seconds" a short introduction to NICER, with NASA Associate Administrator Dr. Thomas Zurbuchen and Dr. Rita Sambruna, NICER program scientist.
  • NICER Press Release: Observations of PSR B1919+21 (02 Aug 2017)
    NICER's science observations have begun. One of the first targets observed was PSR B1919+21, the first pulsar identified 50 years ago by Jocelyn Bell and Anthony Hewish.
  • NICER First Light (17 Jul 2017)
    NASA's new Neutron star Interior Composition Explorer (NICER) mission to study the densest observable objects in the universe has begun science operations. To date, NICER has observed over 40 celestial targets to calibrate the X-ray Timing Instrument and supporting star-tracker camera. The observations also validated the payload's performance that will enable its key science measurements.
  • NICER Status Update (30 Jun 2017)
    NICER commissioning is underway. Fine alignment of the Star Tracker and X-ray Timing Instrument has been completed. The Thermal system is functioning exactly as expected. NICER has observed a number of celestial targets mostly calibration with some observations of NICER science targets.
  • NICER Installed on ELC2 (14 Jun 2017)
    As of June 14, NICER is installed on the ISS Express Logistics Carrier 2 Site 7, and power up of the instrument has begun.
  • Extraction of NICER from the Dragon Trunk (12 Jun 2017)
    This video by made by Mark Egan (MIT) shows NICER being extracted from the Dragon Trunk.
  • Upcoming NICER activities (07 Jun 2017)
    The following is the list of upcoming NICER activities and approximate dates: NICER extracted from the Dragon trunk (June 11); NICER installed on the ISS ELC2 (June 12-13); NICER powered up, deployed, and NICER range of motion verified by robotic camera (June 14); NICER executes initial Pointing control test and Detector initial checkout (June 15); NICER raster scan of Serpens X-1 to determine X-ray instrument and star tracker alignment (June 17); initial calibration and hardware commissioning (June 21-July 12); NICER science program begins (July 13)
  • Dragon Captured (05 Jun 2017)
    The Dragon capsule carrying NICER was successfully captured by the robotic arm on the ISS a bit ahead of the scheduled capture at 10:00 EDT.
  • Rendezvous with ISS and Capture (05 Jun 2017)
    The Dragon capsule, and NICER, will rendezvous with the ISS this morning. Capture of the capsule by the station's robotic arm is scheduled for 10am EDT, and may be viewed live on NASA TV.
  • NICER Launched June 3, 5:07pm EDT (05 Jun 2017)
    The Commercial Resupply Services-11 (CRS-11) mission launched aboard a SpaceX Falcon 9 rocket on June 3, 17:07 EDT (21:07 UTC). CRS-11 marks the first re-use of a Dragon capsule. The CRS-11 payload includes the Neutron Star Interior Composition Explorer (NICER) X-ray timing observatory. NICER is scheduled to be extracted from the Dragon trunk on June 11 and installed onto the Space Station's ExPRESS Logistics Carrier (ELC) on June 13.
  • Current NICER launch date: June 1, 2017 (23 May 2017)
    NICER is currently scheduled for launch to the ISS on SpaceX-11, which is now scheduled for launch on June 1 at 5:55 pm eastern time from the Kennedy Space Center. Backup dates are June 3 (5:04 PM EDT) and 4 (4:44 PM EDT).
  • News Feature: SpaceX Dragon to Deliver Research - including NICER - to the Space Station (22 May 2017)
    SpaceX is scheduled to launch its Dragon spacecraft for its 11th commercial resupply mission to the International Space Station on June 1 from Kennedy Space Center's historic pad 39A. Dragon will lift into orbit atop the Falcon 9 rocket carrying crew supplies, equipment and scientific research, including the NICER payload, to crew members living aboard the station. Once affixed to the exterior of the space station, NICER will study the physics of neutron stars, providing new insight into their nature and behavior.
  • NICER launch date update: June 1, 2017 (02 May 2017)
    NICER is currently scheduled for launch to the ISS on SpaceX-11, which is now scheduled for launch on June 1 at 5:55 pm eastern time from the Kennedy Space Center.
  • NICER expected launch date: May 14, 2017 (21 Mar 2017)
    NICER is currently scheduled for launch to the ISS on May 14, 2017 from the Kennedy Space Center.
  • NICER, the New NASA Mission Studying Neutron Stars, Is On Track for Launch (09 Jun 2016)
    On June 8th, NICER arrived at Kennedy Space Center. The launch for NICER onboard a SpaceX Dragon cargo spacecraft is currently set for February 2017. NICER will deploy as an external attached payload on the ISS ExPRESS Logistics Carrier 2.
  • NICER Passes Pre-Ship Review (25 May 2016)
    NICER has cleared another major milestone review, and the flight payload yesterday passed its Pre-Ship Review at Goddard, and will depart for Kennedy Space Center on June 7. The launch date for NICER is currently scheduled for February 1, 2017.
  • Keith Gendreau, the NICER PI, will be in a Google Hangout on March 18, 3pm EDT (16 Mar 2016)
    The AAS's "Future in Space Hangout" on March 18 at 3pm EDT will feature the CATS (Cloud-Aerosol Transport System) and NICER (Neutron star Interior Composition Explorer) payloads on the ISS, with Keith Gendreau the NICER PI participating. The hangout will address questions such as how missions are selected to run on the ISS and what the technical challenges are building instruments for operation onboard the ISS.
  • NICER Passes Pre-Environmental Review (14 Dec 2015)
    NICER has cleared another major milestone review, and the nearly-complete flight payload is poised to begin environmental (electromagnetic, vibration, thermal, etc.) testing. Delivery to NASA's Kennedy Space Center is anticipated in June 2016 for the planned August launch.
  • NICER Manifested on SpaceX-11 ISS Resupply Flight (01 Dec 2015)
    Previously scheduled for a December 2016 launch on SpaceX-12, NICER will now fly to the International Space Station with two other payloads on SpaceX Commercial Resupply Services (CRS)-11, in the Dragon vehicle's unpressurized Trunk. Launch is planned for no earlier than 15 August 2016, from Cape Canaveral Air Force Station in Florida.
  • NICER Blanketeer Featured on CBSnews (06 Jul 2015)
    Paula Cain, who makes the blanket which will protect NICER, was featured on
  • NICER Project Systems Engineer Featured on (06 Jul 2015)
    Charles Baker, the Project Systems Engineer for NICER, was interviewed on
  • NICER Passes Critical Design Review (19 Sep 2014)
    NICER unanimously passed its CDR "with flying colors".
  • NICER at the HEAD Meeting (17 Aug 2014)
    The NICER Special Session at the 2014 meeting of the High Energy Astrophysics Division (HEAD) of the American Astronomical Society will be held on Wednesday, August 20, at 1:30 pm in the Great Lakes Grand Ballroom of the Westin Michigan Avenue hotel in Chicago. Please join us!
  • NICER Critical Design Review (16 Aug 2014)
    NICER's next step towards launch, the Critical Design Review, is planned for September 2014. NICER remains on-track for launch on the SpaceX-12 ISS resupply flight currently scheduled for October 2016.
  • Upcoming NICER Presentations Announced (03 Apr 2014)
    There will be an overview presentation on the NICER mission design at the SPIE "Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray" conference in Montreal in June, 2014, and NICER science will be the subject of a Special Session at the High-Energy Astrophysics Division (HEAD) meeting in Chicago in August, 2014.
  • Forward to Phase C (31 Mar 2014)
    NICER's engineers and scientists have successfully passed several major project milestones, including a Preliminary Design Review by an independent team of experts, an initial Payload Safety Review by an International Space Station (ISS) panel, and a Confirmation Review at NASA HQ. NICER is now in Phase C.
  • NICER and the Upcoming Zombie Star Apocalypse (05 Apr 2013)
    NASA Taps the Power of Zombie Stars in a Two-in-One Instrument called NICER.
  • NASA Selects NICER for Development (05 Apr 2013)
    NASA's Astrophysics Explorer Program has selected two missions for launch in 2017: a planet-hunting satellite and an International Space Station instrument to observe X-rays from neutron stars, NICER.
  • NICER/SEXTANT team chosen NASA/GSFC Innovators of the year (02 Dec 2011)
    Goddard technologist Keith Gendreau and the NICER/SEXTANT team were named this year's "Innovators of the Year." The Goddard Office of the Chief Technologist bestows the award annually on technologists who exemplify the best in R & D.
  • NICER helping to Educate the Next Generation of Scientists (24 Oct 2011)
    Student involvement in NICER
  • NASA Selects NICER For Concept Study (29 Sep 2011)
    NASA has selected 11 science proposals, including the Neutron star Interior Composition ExploreR (NICER), for evaluation as potential future science missions. The proposals outline prospective missions to study the interior of neutron stars, Earth's atmosphere, the sun, the Milky Way galaxy, and Earth-like planets around nearby stars.

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