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"21208 results found.
- GRB 101030A: Enhanced Swift-XRT position
- GRB 101030A: Swift detection of a burst
- GRB 090111, the review of the sky area in plate archives (1976-1996)
- Konus-Wind observation of GRB 101023A
- GRB 101024A: GROND optical/NIR observations
- GRB 101024A: Zadko observatory - Gingin. Optical observations
- GRB 101024A: Fermi GBM observation
- GRB101024A: Swift/UVOT
- GRB 101024A: Enhanced Swift-XRT position
- Swift/UVOT observations of GRB101023A
- GRB 101024A: Swift detection of a burst with an optical afterglow
- GGRB 101023A: GROND detection of the optical-NIR afterglow
- GRB 101023A: Swift-BAT refined analysis
- GRB 101023A: Gemini discovery of optical afterglow
- GRB 101023A: Enhanced Swift-XRT position
- GRB 101023A: REM NIR observations
- GRB 101023A: Swift detection of a burst
- GRB 101020A, Swift-BAT refined analysis
- GRB 101017A: Swift/UVOT Observations
- GRB 101008A: optical observations
- GRB101017A: MITSuME Okayama optical upper limits
- Konus-Wind observation of GRB 101017A
- GRB 101017A: Enhanced Swift-XRT position
- GRB 101017A: Swift-BAT refined analysis
- GRB 101017A: ROTSE-III Optical Limits
- GRB 101017A: Swift detection of a burst with optical counterpart
- Konus-Wind observation of GRB 101014A
- GRB 100902A: D50 optical limit
- GRB 101011A: Swift/UVOT observations
- GRB 101011A, GROND upper limits
- GRB 101011A: Zadko observatory - Gingin optical observations
- GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
- GRB 101011A: Enhanced Swift-XRT position
- GRB 101011A: Swift detection of a burst
- GRB101008A, GROND detection of a fading afterglow
- GRB 101008A: SAO RAS optical observations
- GRB 100915 optical upper limit
- GRB 101008: Swift/UVOT Upper Limits
- GRB 101008A: Enhanced Swift-XRT position
- GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
- Swift Trigger 435520 is probably not a GRB
- GRB 100924A: Suzaku WAM observation of the prompt emission
- GRB100925A/MAXI J1659-152 MITSuME Ishigakijima and Okayama Optical Observation
- GRB 100925A / MAXI J1659-152: SARA-S Observations
- GRB 100925A/MAXI J1659-152: Submm observations from APEX
- GRB 100925A/MAXI J1659-152 - NOT optical observations
- GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
- GRB 100924A: GROND detection of an optical/NIR afterglow
- GRB 100925A: Swift detection of a burst
- GRB 100917A: TAROT La Silla observatory optical observations
- GRB 100915A: TAROT Calern observatory optical observations
- GRB100906A: Ashra-1 observation of early optical emission
- GRB 100917A: Swift-BAT refined analysis
- GRB100915A: MITSuME Ishigakijima Optical upper limits
- GRB 100915B: GRT Optical Observation
- GRB 100915A: GRT Optical Observation
- GRB 100915A: Swift/UVOT Upper Limits
- GRB 100915A: Swift-BAT refined analysis
- GRB 100915A: Enhanced Swift-XRT position
- GRB 100915A: Swift detection of a likely burst
- Swift BAT Trigger 433953 probably not a GRB
- GRB100909A: MITSuME Ishigakijima Optical upper limits
- GRB 100909A: Swift/UVOT observations
- GRB 100901A: errata of GRB name in GCN 11270
- GRB 100901A: optical observations in Mondy and R-light curve
- GRB 100909A: Swift-XRT refined analysis
- GRB 100906A: optical observations at Mt.Terskol
- GRB 100901A: optical observation in Maidanak, break confirmation
- GRB 100909A: ROTSE-III Optical Limits
- GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
- GRB 100909A: Swift target of opportunity observation
- GRB100906A: detection at 15GHz
- GRB100901A: IAO optical upper limits at 4 days after the burst
- GRB 100901A: CrAO optical observations
- GRB100906A: R band observations
- Konus-Wind observation of GRB 100906A
- GRB100906A: non-detection at 15GHz
- GRB100906A: Optical observations at IAO
- GRB 100906A: Enhanced Swift-XRT position
- GRB 100906A: Swift/UVOT Observations
- GRB100906A: MITSuME Okayama Optical Observation
- GRB 100905A: Swift/UVOT Upper Limits
- GRB 100901A: TLS observations, SDSS calibration, decay slope
- GRB 100906A: Swift-BAT refined analysis
- GRB 100906A: Swift detection of a burst with an optical afterglow
- GRB 100829A: MASTER optical observations
- GRB100905A: Optical upper limits at IAO
- GRB100905A: MITSuME Okayama optical upper limits
- GRB100905A: 1.5m OSN upper limit
- GRB 100905A: Enhanced Swift-XRT position
- GRB 100905A: Swift detection of a burst
- GRB10901A: Murikabushi telescope observation at 3 days after the burst
- GRB 100901A: Submm observations from SMA
- GRB100902A: Optical upper limits at IAO
- GRB10901A: Optical observations at IAO
- Konus-Wind observation of GRB 100829A
- IPN Triangulation of the very bright GRB 100829A
- Tentative redshift of GRB100902A from Swift-XRT data
- GRB 100902A: Swift/UVOT Upper Limits
- GRB 100902A: optical observation at Mt.Terskol