GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"7448 results found.
- LIGO/Virgo S190910d : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190910d: Upper limits from Fermi-GBM Observations
- ZTF19abvizsw: No counterpart candidates from Swift/BAT targeted search
- LIGO/Virgo S190910d: No counterpart candidates in HAWC observations
- LIGO/Virgo S190910d: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190910d: Upper limits from IceCube neutrino searches
- ZTF19abvizsw/AT2019pim, search for GRB in SPI-ACS/INTEGRAL data
- LIGO/Virgo S190901ap: ZTF19abwvals is a type-Ia SN near maximum
- LIGO/Virgo S190901ap: Second Epoch Hobby-Eberly Telescope observations of ZTF19abvionh
- LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
- LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate MASTER OT J171434.95+280725.6
- LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
- LIGO/Virgo S190901ap: Additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
- LIGO/Virgo S190901ap : GRAWITA photometric observation of candidate ZTFabvizsw and GCN 25618 revision
- LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
- Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
- LIGO/Virgo S190901ap: Additional observations from the Zwicky Transient Facility
- LIGO/Virgo S190901ap: GROWTH-India follow-up of ZTF19abvionh
- Chandra observations of GW170817 ~740-743 days since merger
- LIGO/Virgo S190901ap: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190828l: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190828j: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190901ap: No neutrino candidates at Pierre Auger Observatory
- LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh
- LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvixoy
- LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvizsw
- LIGO/Virgo S190901ap: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190901ap: Updated Sky Localization
- LIGO/Virgo S190901ap : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190901ap: No counterpart candidates in HAWC observations
- LIGO/Virgo S190901ap: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190901ap: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidate AT2019ntp
- GRB 190829A: No Neutrino Counterpart detected with ANTARES
- LIGO/Virgo S190814bv: Upper limits from a two-week IceCube search for neutrinos from the direction of ASKAP J005547-270433
- LIGO/Virgo S190829u: Retraction of GW compact binary merger candidate
- GRB 190829A: Swift detection of a burst consistent with a galaxy at z=0.08
- GRB 190828B: VLT/X-shooter optical afterglow candidate
- LIGO/Virgo S190426c: Update on Probability of Terrestrial Origin
- LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx
- LIGO/Virgo S190814bv: VLA observation of ASKAP J005547-270433/AT2019osy
- GRB 190828A: Tiled Swift observations
- LIGO/Virgo S190814bv: Swift UVOT - no new counterpart candidates identified
- LIGO/Virgo S190828l: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190828j: Upper limits from Fermi-GBM Observations
- GRB 190828B: Swift detection of a burst
- LIGO/Virgo S190828l: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190828l: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190828j: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190828j : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190828l : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190828j: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190828j: Updated Sky Localization
- LIGO/Virgo S190828l: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190828l: No counterpart candidates in HAWC observations
- LIGO/Virgo S190828j: No counterpart candidates in HAWC observations
- LIGO/Virgo S190828j: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190814bv: Correction of ASKAP coordinates
- LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433
- LIGO/Virgo S190814bv: Optical non-detection of radio source AT2019osy from CFHT
- Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: Detection of a candidate radio counterpart with ASKAP
- LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign
- LIGO/Virgo S190814bv: CFHTphotometryof AT2019npv
- LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num
- LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc
- LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field
- Fermi GBM-190816: Updated localization of subthreshold GRB-GW candidate
- GRB 190824A: Swift detection of a burst
- LIGO/Virgo S190814bv: Keck NIRES spectroscopy of DG19wxnjc/AT2019npv
- GRB 190823A: Tiled Swift observations
- LIGO/Virgo S190814bv: DESGW photometry of AT2019npv
- LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
- LIGO/Virgo S190814bv: ENGRAVE VLT/HAWK-I observations and archival detection of the CFHT candidate
- LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
- LIGO/Virgo S190814bv: a potential faint optical counterpart in CFHT imaging
- LIGO/Virgo S190822c: Retraction of GW compact binary merger candidate
- LIGO/Virgo S190822c: CLU/NED Galaxies in the 50% Localization Volume
- LIGO/Virgo S190822c: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190814bv: new candidate from DESGW
- GRB 190821A: MASTER do not see any afterglow candidate
- Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
- GRB 190821A: Swift detection of a burst
- LIGO/Virgo S190814bv: further candidates from DESGW
- Fermi GBM-190816: AGILE in SAA at T0
- LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019noq and AT2019ntn
- Fermi GBM-190816: One candidate counterpart from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: Further Pan-STARRS observations and transient sources
- Fermi GBM-190816: Upper limits from IceCube neutrino searches
- Fermi GBM-190816: No counterpart candidates in HAWC observations
- LIGO/Virgo S190814bv: No neutrino candidates at Pierre Auger Observatory
- Fermi GBM-190816+LIGO/Virgo : no neutrino counterpart candidate in ANTARES search
- Fermi GBM-190816: A subthreshold GRB candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
- IceCube-190819A: Upper limits from Fermi-GBM Observations
- IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- IceCube-190819A - IceCube observation of a high-energy neutrino candidate event
- LIGO/Virgo S190814bv: GRAWITA TNG NIR imaging of AT2019nqq and AT2019nqc
- LIGO/Virgo S190814bv: DESGW candidate update