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"19548 results found.
- LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190923y : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190923y: No counterpart candidates in HAWC observations
- IceCube-190922A - HAWC follow-up
- IceCube-190922A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190814bv: HST and ALMA observations of the host galaxy of ASKAP J005547-270433 / AT 2019osy
- GRB 190919B: Swift/UVOT Upper Limits
- GRB 190919B: Swift ToO observations
- GRB 190919B: GROND detection of the NIR afterglow
- HAWC-190916A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- HAWC-190916A: DDOTI Optical Observations
- Alert from the HAWC Burst Monitor HAWC-190917A
- LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190915ak : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190910d: No Counterparts in DDOTI/OAN Optical Observations
- LIGO/Virgo S190910d: No neutrino candidates at Pierre Auger Observatory
- LIGO/Virgo S190910h: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190910h: No counterpart candidates in HAWC observations
- LIGO/Virgo S190910h : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190910d: no counterpart candidates in the Swift/BAT Observations
- Swift Trigger 924641 is an outburst from MAXI J1807+132
- LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190910d : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- 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 S190814bv: ATCA monitoring of ASKAP J005547-270433/AT2019osy
- LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations
- ZTF19abvizsw: 15GHz observations with AMI
- GRB 190823A: Swift-XRT afterglow detection
- IPN triangulation of GRB 190906A (short)
- GRB 190829A: GTC confirmation of an associated Type Ic-BL Supernova
- GRB 180620A: SEDM Observations
- LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery.
- LIGO/Virgo S190901ap: NOT spectroscopy of AT2019pjv
- LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
- ZTF19abvizsw: COATLI Optical Observations
- LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
- 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 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: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh
- LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of target galaxy; no obvious optical counterpart.
- LIGO/Virgo S190901ap: no counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190901ap: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190901ap : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190901ap: No counterpart candidates in HAWC observations
- LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
- LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
- GRB 190829A: KAIT Detection of the Optical Afterglow
- GRB 190829A: AGILE ratemeters detection and MCAL upper limits
- GRB 190829A: Fermi-LAT Upper Limits
- GRB 190829A: Swift/UVOT detection of an optical afterglow with a rise
- GRB 190829A: GROND detection of the Optical/NIR Afterglow
- GRB 190829A: Enhanced Swift-XRT position
- GRB 190829A: NOT optical afterglow detection and spectroscopy
- LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations
- GRB 190829A: GROWTH India detection of afterglow
- GRB 190829A: Dabancheng-0.5m optical afterglow detection
- GRB 190829A: Swift detection of a burst consistent with a galaxy at z=0.08
- GRB 190828B: VLT/X-shooter optical afterglow candidate
- GRB 190828B: optical upper limit from 0.5m Savelli Robotic Telescope
- LIGO/Virgo S190814bv: Swift observation of ASKAP J005547-270433/AT2019osy
- GRB 190828B: Swift/UVOT Upper Limits
- GRB 190828A: Swift-XRT observations
- LIGO/Virgo S190828l: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190828l: no counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190828j: no counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190828j: No counterpart candidates in Fermi-LAT observations
- GRB 190828A: Tiled Swift observations
- LIGO/Virgo S190814bv: no variation of DESGW candidates AT 2019onj and AT 2019okr from ENGRAVE VLT/HAWK-I observations, and archival detection
- GRB 190828B: Dabancheng-0.5m optical upper limit
- GRB 190828B: Enhanced Swift-XRT position
- GRB 190828B: Swift detection of a burst
- LIGO/Virgo S190828j: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190828j : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190828l : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190828l: No counterpart candidates in HAWC observations
- LIGO/Virgo S190828j: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190828j: No counterpart candidates in HAWC observations
- LIGO/Virgo S190814bv: Correction of ASKAP coordinates
- GRB 190824A: Swift/UVOT Upper Limits
- LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field
- GRB 190816A: Swift-XRT afterglow detection