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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"26249 results found.
- GRB 090831C: GROND upper limits
- Swift Trigger 361477, called GRB090831B, is probably not real.
- GRB090831C: Swift/UVOT upper limits
- GRB 090831C: Swift XRT Refined Analysis
- GRB 090829B: Fermi GBM Detection
- GRB 090831C: Swift detection of a burst
- GRB 090831B, RIMOTS optical upper limits
- GRB 090831: MAXI GSC detection
- GRB 090831B: Swift detection of a possible burst
- GRB 090831: Fermi GBM detection
- GRB090829: Fermi GBM Detection
- GRB 090827: Swift XRT and UVOT observations
- GRB 090827 Burst discovered in BAT ground analysis
- GRB 090826: Fermi GBM detection
- GRB 090828: Fermi GBM detection
- Fermi Gamma-ray Burst Monitor trigger 273123112 is not a GRB
- GRB 090823: Swift XRT possible detection of the X-ray afterglow
- GRB 090817: Swift/UVOT Observations of a Possible Late-Time Brightening
- GRB 090820: detection of a strong burst by RT-2 on board CORONAS PHOTON
- GRB 090820B: Fermi GBM detection
- GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
- GRB 090820: Fermi GBM Detection of a bright burst.
- GRB 090815C: Swift refined analysis
- GRB 090817: Fermi GBM observation
- GRB 090817: Swift/UVOT Upper Limits
- GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090813: Suzaku WAM observation of the prompt emission
- GRB 090812: Suzaku WAM observation of the prompt emission
- GRB 090815B: Fermi GBM detection
- GRB 090815: Fermi GBM detection
- Fermi Gamma-ray Burst Monitor trigger 271934815 is not a GRB
- GRB 090814C: Fermi GBM detection
- GRB 090814A: Swift/UVOT Observations
- GRB 090814A: Swift-XRT Team Refined Analysis
- GRB 090814A, RIMOTS optical upper limits
- GRB 090814A: Swift-BAT refined analysis
- GRB 090814: GROND Detection of an Optical Afterglow Candidate
- GRB 090814: Swift detection of a burst
- GRB 090813: Fermi GBM observation
- Fermi Gamma-ray Burst Monitor trigger 271446248 is not a GRB
- GRB 090813: Swift-XRT refined analysis
- Fermi Gamma-ray Burst Monitor trigger 271833016 is not a GRB
- GRB 090813, Swift-BAT refined analysis
- Konus-Wind observations of GRB090813
- GRB090813: Swift/UVOT upper limits
- GRB 090813: Liverpool Telescope afterglow confirmation
- GRB 090813: optical candidate from 1.23m CAHA telescope
- GRB 090813: Swift detection of a burst
- GRB 090812: WIRO NIR upper limit
- GRB 090812: Faulkes Telescope South Continued Optical Monitoring
- GRB 090812: RAPTOR detections during the burst
- GRB 090812: Swift XRT refined analysis
- GRB 090812, RIMOTS optical upper limits
- GRB 090812 Swift-BAT Refined Analysis
- GRB090812: Swift/UVOT observations
- GRB 090812: GROND Observations of the Optical/NIR Afterglow
- GRB 090812: Liverpool Telescope afterglow confirmation
- GRB 090812: Swift detection of a burst with an optical counterpart
- GRB 090807B: Fermi GBM detection
- GRB 090809B: Fermi GBM detection
- GRB 090809: Swift-XRT refined analysis
- GRB090809: Swift/UVOT observations
- GRB 090809: Swift-BAT refined analysis
- GRB 090809: Swift detection of a burst with a possible optical counterpart
- GRB 090807: Liverpool Telescope observations
- GRB 090807: Swift/UVOT Upper Limits
- GRB 090807: Swift-XRT refined analysis
- GRB 090807, Swift-BAT refined analysis
- GRB 090807, RIMOTS optical upper limits
- GRB 090807: Swift detection of a burst
- Fermi Gamma-ray Burst Monitor trigger 271275771 is not a GRB
- GRB 090802B: Fermi GBM detection
- GRB 090802: Fermi GBM detection
- Swift-BAT trigger 358760 is most likely not a GRB
- Swift trigger 358760 is probably a noise event
- GRB 090717A: Suzaku WAM observation of the prompt emission
- GRB 090709A : Quick look analysis of the Suzaku observation
- GRB 090728: Swift-BAT refined analysis
- GRB 090727: GRT Optical Observation
- GRB 090728: Swift XRT refined analysis
- GRB 090727: optical observations
- GRB 090726: GRT Optical Observation
- GRB 090727: Swift/UVOT Upper Limits
- GRB 090728: Swift/UVOT Upper Limits
- GRB 090728, RIMOTS optical upper limits
- GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
- GRB 090728: Swift detection of a burst
- GRB 090727: Swift-BAT refined analysis
- GRB 090727: Swift-XRT refined analysis
- GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
- GRB 090727: Liverpool Telescope possible OT candidate
- GRB 090727: Swift detection of a burst
- GRB090726: Swift/UVOT observations
- GRB 090726, Swift-BAT refined analysis
- GRB 090726: D50 optical observations
- GRB 090711: Fermi GBM detection
- GRB090726: 6-meter telescope redshift
- GRB 090726: Swift-XRT Team refined analysis
- GRB 090726: optical transient candidate
- GRB 090726: Swift/UVOT Finding Chart Observation