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"5812 results found.
- LIGO/Virgo S190924h: No counterpart candidates in AGILE-MCAL observations
- Fermi-LAT Gamma-ray Observations of IceCube-190922B
- LIGO/Virgo S190924h: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- LIGO/Virgo S190924h : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190923y: No counterpart candidates in Fermi-LAT observations
- IceCube-190922B: Upper limits from a search for additional neutrino events in IceCube
- IceCube-190922A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo S190924h: Global MASTER-Net observations report
- LIGO/Virgo S190923y: Upper limits from CALET observations.
- LIGO/Virgo S190924h: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190924h: Upper limits from IceCube neutrino searches
- Fermi-LAT Gamma-ray Observations of IceCube-190922A
- IceCube-190922B - HAWC follow-up
- LIGO/Virgo S190923y: INTEGRAL IBIS coded-masked imaging observations of part of the localization area and further all-sky upper limits
- IceCube-190922B: Identification of a Candidate Supernova from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
- LIGO/Virgo S190923y: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190923y: No counterpart candidates in AGILE-MCAL observations
- 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: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190923y: Global MASTER-Net observations report
- LIGO/Virgo S190923y: Upper limits from IceCube neutrino searches
- Fermi trigger No 590899086: Global MASTER-Net observations report
- IceCube-190922B: INTEGRAL was inactive at the time of the event
- IceCube-190922B - IceCube observation of a high-energy neutrino candidate event
- IceCube-190922A - HAWC follow-up
- IceCube Alert 190922.96: Global MASTER-Net observations report
- IceCube-190922A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- IceCube-190922A - IceCube observation of a high-energy neutrino candidate event
- Fermi trigger No 590777160: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 190920.65: Global MASTER-Net observations report
- Integral GRB190919.99: Global MASTER-Net observations report
- Fermi trigger No 590621700: Global MASTER-Net observations report
- Fermi trigger No 590610007: Global MASTER-Net observations report
- LIGO/Virgo S190915ak: No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190910h: No significant candidates in TAROT-GRANDMA observations
- HAWC-190916A: Upper limits from Insight-HXMT/HE observations
- HAWC-190916A: IceCube neutrino search
- HAWC-190916A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190915ak: No transient candidates in CALET observations
- HAWC-190916A: DDOTI Optical Observations
- Fermi trigger No 590335819: Global MASTER-Net observations report
- LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
- GRB 190915A: Insight-HXMT/HE detection
- GRB190915A: MASTER optical observation of BALROG Fermi GRB localization
- LIGO/Virgo S190915ak : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190915ak: Upper Limits from AGILE-GRID observations
- LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations
- LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190915ak: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190915ak: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190915ak: Global MASTER-Net observations report
- LIGO/Virgo S190910d : No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey.
- Fermi trigger No 590038994: Global MASTER-Net observations report
- LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190910d: MASTER previous detection of Gaia19eba/AT2019qam
- LIGO/Virgo S190910h: Gaia Photometric Alerts transient candidates
- LIGO/Virgo S190910d: Gaia Photometric Alerts transient candidate
- Baksan Neutrino Observatory Alert 190913.27: Global MASTER-Net observations report
- LIGO/Virgo S190910d: No Counterparts in DDOTI/OAN Optical Observations
- GRB 190913A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190910h: Upper limits from CALET observations.
- LIGO/Virgo S190910d: No transient candidates in CALET observations.
- LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT observations
- LIGO/Virgo S190910d: No neutrino candidates at Pierre Auger Observatory
- LIGO/Virgo S190910h: Four additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190910h: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190910d: Liverpool Telescope spectroscopy of ZTF19abyfazm
- LIGO/Virgo S190910d: AstroSat CZTI upper limits
- LIGO/Virgo S190910h: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190901ap: Gaia Photometric Alerts transient candidates
- LIGO/Virgo S190910h: No counterpart candidates in AGILE-MCAL observations
- LIGO/Virgo S190910h Global MASTER-Net observations report
- 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 S190910h: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190910h: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190910d: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190910d: no counterpart candidates in AGILE-GRID observations
- LIGO/Virgo S190910d: no counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190910d: No counterpart candidates in AGILE-MCAL 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: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190910d Global MASTER-Net observations report
- LIGO/Virgo S190910d: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190901ap: Gaia Photometric Alerts transient candidates
- LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations
- GRB 190901A: AstroSat CZTI detection