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"4055 results found.
- LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G275697: REM optical/NIR observations
- LIGO/Virgo G275697: Konus-Wind observations
- LIGO/Virgo G275404: CNEOST optical observations
- LIGO/Virgo G275697: Swift-XRT sources
- LIGO/Virgo G275697: Swift/BAT data search
- LIGO/Virgo G275404: MASTER bright PSN detected on 27 Feb from the maximum of probability of LIGO localization
- LIGO/Virgo G275697: AGILE-GRID preliminary analysis
- LIGO/Virgo G275697: AGILE MCAL Observations
- LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/VIRGO G275697: Fermi GBM Observations
- LIGO/Virgo G275404: AstroSat CZTI upper limits
- LIGO/Virgo G275697 ANTARES search
- LIGO/Virgo G275697: IceCube neutrino observations
- LIGO/Virgo G275697: Identification of a GW CBC Candidate
- LIGO/Virgo G275404: Keck LRIS classification of MASTER PSN candidate
- LIGO/Virgo G274296: MASTER new PSN detected on 22 feb
- LIGO/Virgo G275404: REM optical/NIR observations
- LIGO/Virgo G275404: MASTER PSN detection from the maximal probability LIGO region
- LIGO/Virgo G275404: MASTER OT is outside LIGO error region
- LIGO/Virgo G275404: Keck spectrum of MASTER OT J105958.00-115756.5
- LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G275404: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/Virgo G275404: AGILE-GRID detection of a possible gamma-ray transient
- LIGO/Virgo G275404: NOT Follow-up of MASTER OT
- LIGO/Virgo G275404: Swift-XRT sources
- LIGO/Virgo G275404 ANTARES search
- LIGO/Virgo G275404: Follow-up of MASTER OT J173532.70+103810.5
- LIGO/Virgo G275404: MASTER bright OT detection
- LIGO/Virgo G274296: P200 classification of EM candidates
- LIGO/Virgo G275404: Swift/BAT data search
- LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
- LIGO/Virgo G274296: Swift/BAT data search
- LIGO/Virgo G275404: AGILE-GRID preliminary analysis
- LIGO/Virgo G275404: Fermi GBM Observations
- LIGO/Virgo G275404: AGILE MCAL observations
- LIGO/Virgo G275404: MASTER Tunka OT detection
- LIGO/Virgo G275404: IceCube neutrino observations
- LIGO/Virgo G275404: Identification of a GW CBC Candidate
- LIGO/Virgo G275404: MASTER automatic follow up observations
- LIGO/Virgo G274296: GRAWITA-Campo Imperatore observation
- LIGO/Virgo G274296: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G274296: MASTER new OT
- LIGO/Virgo G274296: CALET Observations
- LIGO/Virgo G274296: HAWC follow-up
- LIGO/Virgo G274296: No change to estimate of LIGO false alarm probability
- LIGO/Virgo G274296: PIRATE Observations
- IPN Triangulation of GRB 170222A (short/hard)
- LIGO/Virgo G274296: PS17bek is a superluminous supernova at z=0.31
- LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
- LIGO/Virgo G274296: iPTF Optical Transient Candidates
- LIGO/Virgo G274296: Kanata 1.5m optical spectroscopy of MASTER optical transient
- LIGO/Virgo G274296: Global MASTER Net PSN and QSO detection
- LIGO/Virgo G274296: Asiago 1.82m Optical Observations
- LIGO/Virgo G274296: ATLAS confirmation of the bright MASTER transient and earlier explosion date
- LIGO/Virgo G274296: MASTER new bright possible SN detection and inspection dinamic
- LIGO/Virgo G274296: PSN MASTER OT J042250.16-820415.4 is before maximum
- LIGO/Virgo G274296: IceCube neutrino observations
- LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
- LIGO/Virgo G274296: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G274296: AstroSat CZTI upper limits
- LIGO/Virgo G274296 ANTARES search
- IPN Triangulation of GRB 170219A (short/hard)
- LIGO/Virgo G274296: Optical Observation
- LIGO/Virgo G274296: CNEOST imaging coverage and an optical transient
- LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
- LIGO/Virgo G274296: SWASP optical imaging coverage
- LIGO/Virgo G274296: Global MASTER Net two OTs detection
- LIGO/Virgo G274296: Global MASTER Net SN bright detection during GW error box inspection
- LIGO/Virgo G274296: Observations of initial skymap by project Mini-GWAC of SVOM
- LIGO/Virgo G274296: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/Virgo G274296: REM optical/NIR observations
- LIGO/VIRGO G274296: Fermi GBM Observations
- LIGO/VIRGO G274296: AGILE-GRID preliminary analysis
- LIGO/Virgo G274296: Identification of a GW Burst Candidate
- LIGO/Virgo G270580: DLT40 follow-up observation
- LIGO/Virgo G270580: AstroSat CZTI upper limits
- IPN Triangulation of GRB 170207A (long/very bright)
- LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
- LIGO/Virgo G270580: ANTARES upper limits
- LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
- LIGO/Virgo G268556: FLOYDS Spectrum of iPTF17cf/PS17fr Favors an AGN Classification
- LIGO/Virgo G270580: HAWC follow-up observations
- LIGO/Virgo G270580: Swift/UVOT follow-up of PS17yt
- LIGO/Virgo G270580: Fermi GBM Observations
- LIGO/Virgo G270580: MAXI/GSC observations
- LIGO/Virgo G270580: NOT observations of PS17yt
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G270580: Asiago 1.82m observations of PS17ua and PS17yt
- LIGO/Virgo G270580: Swift-XRT follow-up of PS17yt
- LIGO/Virgo G270580: GMG photometric follow-up of PS17yt
- LIGO/Virgo G270580: 10.4m GTC spectroscopic observations of PS17yt
- LIGO/Virgo G270580: No change to estimate of LIGO false alarm probability
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
- LIGO/Virgo G268556: ANTARES upper limits
- LIGO/Virgo G270580: UL50 observations
- LIGO/Virgo G270580: CALET Observations
- LIGO/Virgo G270580: Pan-STARRS coverage and bright, rising transient PS17yt
- LIGO/Virgo G270580/GW170120 : Asiago observations