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"28090 results found.
- GRB 090831A: Suzaku WAM observation of the prompt emission
- GRB 090904B: Swift/UVOT Refined Analysis
- GRB 090902B: Suzaku WAM observation of the prompt emission
- GRB 090829A: Suzaku WAM observation of the prompt emission
- GRB 090904B: Fermi GBM detection
- GRB 090904A: Swift-XRT refined analysis
- GRB 090904B: Swift XRT Refined Analysis
- GRB 090904B: Swift-BAT refined analysis
- GRB 090902B: VLA radio detection
- GRB 090904A: Swift-BAT refined analysis
- GRB 090904B: Enhanced Swift-XRT position
- GRB 090904A: Enhanced Swift-XRT position
- GRB 090904A: NOT observations
- GRB090904B: REM observations
- GRB 090904B: Swift detection of a burst
- GRB 090904: Swift detection of a burst
- GRB 090902B: Swift/UVOT refined analysis
- GRB090902B: Swift XRT refined analysis
- GRB 090902B: Faulkes Telescope North observations
- GRB 090902B: GROND NIR Afterglow Observations
- GRB 090902B: Enhanced Swift-XRT position
- GRB 090902B: Optical afterglow candidate
- GRB090902B: Swift/UVOT observations
- GRB 090902B: Swift/XRT Afterglow Candidate
- GRB 090902B: Fermi LAT detection
- GRB 090902B: Fermi GBM detection of a bright burst
- GRB 090902: Fermi GBM detection
- GRB 090831A: IPN Triangulation
- GRB 090831C BAT refined analysis
- GRB 090831C: GROND upper limits
- Swift Trigger 361477, called GRB090831B, is probably not real.
- GRB090831C: Swift/UVOT upper limits
- GRB 090831B: MITSuME optical upper limits
- GRB 090831C: Swift XRT Refined Analysis
- GRB 090829B: Fermi GBM Detection
- GRB 090831C: Enhanced Swift-XRT position
- 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
- GRB 090817 - TLS Observations
- GRB 090823: Swift XRT possible detection of the X-ray afterglow
- GRB 090823 Long burst with IPN triangulation and BAT position
- GRB 090820B: Fermi GBM detection
- GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
- GRB 090820: MASTER-Net optical polarization observations
- GRB 090820: Fermi GBM Detection of a bright burst.
- GRB 090817: optical upper limit
- GRB 090817: Confirmation of the X-ray afterglow
- 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 090817: Swift-XRT observations
- GRB 090814A: optical observations
- GRB 090813: Suzaku WAM observation of the prompt emission
- GRB 090812: Suzaku WAM observation of the prompt emission
- VLA radio non-detection of GRB 090812
- GRB 090815B: Fermi GBM detection
- GRB 090815: Fermi GBM detection
- GRB 090813: CrAO optical obsevations
- GRB090814A: NOT optical follow-ups
- GRB 090814B: Swift/UVOT Upper Limits
- GRB 090814B: Liverpool Telescope Observations
- GRB 090814C: Fermi GBM detection
- GRB 090814B: Swift-XRT detection of a possible afterglow.
- GRB 090814A: Swift/UVOT Observations
- GRB 090814A: Swift-XRT Team Refined Analysis
- GRB 090814A, RIMOTS optical upper limits
- GRB 090814A: Swift-BAT refined analysis
- GRB090814A: VLT spectroscopy
- GRB 090814: Enhanced Swift-XRT position
- GRB 090814: GROND Detection of an Optical Afterglow Candidate
- GRB 090814: Swift detection of a burst
- GRB 090813: Swift-XRT refined analysis
- GRB 090813, Swift-BAT refined analysis
- Konus-Wind observations of GRB090813
- GRB090813: Swift/UVOT upper limits
- GRB 090813: Enhanced Swift-XRT position
- GRB 090813: Liverpool Telescope afterglow confirmation
- GRB 090813: P60 Optical Afterglow Confirmation
- GRB 090813: Swift detection of a burst
- 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: Enhanced Swift-XRT position
- GRB 090812: P60 Confirmation of Optical Afterglow
- GRB 090812: Swift detection of a burst with an optical counterpart
- GRB 090807B: Fermi GBM detection
- GRB 090809: Further NOT optical observations