GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"- GRB 130514A: Swift-BAT refined analysis
- GRB 130513A: Swift-XRT detection of the afterglow.
- GRB 130514A: GROND optical-NIR afterglow discovery and photo-z
- GRB 130514A: P60 Observations
- GRB 130514A: Swift detection of a burst
- GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
- GRB 130513A: a long GRB detected by INTEGRAL
- GRB130508A: MASTER-Net optical observations
- GRB130511A: SOAO Optical Observation
- GRB 130511A: Swift-XRT refined Analysis
- GRB 130511A: Kanata/HOWPol optical observation
- GRB 130511A: MITSuME Okayama upper limits
- GRB 130511A, Swift-BAT refined analysis
- GRB 130511A: Upper limit by Xinglong TNT optical observation
- GRB 130511A: Enhanced Swift-XRT position
- GRB 130511A: Gemini-North Redshift
- GRB 130511A: Swift detection of a burst with an optical counterpart
- GRB 130508A: Swift/UVOT Upper Limits
- GRB 130508A: MITSuME Akeno upper limits
- GRB 130427A: host galaxy observations
- GRB 130508A: RATIR Optical and NIR Observations
- GRB 130427A: Keck/LRIS Observations
- GRB 130508A: Refined Swift-XRT analysis: Correction to GCN 14612
- GRB 130508A, Swift-BAT refined analysis
- GRB 130508A: MITSuME Okayama upper limits
- Fermi Trigger 130507.091 - Detection of a SGR-like Burst
- GRB130508A: BOOTES-3 optical limit
- GRB 130427A: Ten nights of Skynet/PROMPT/GORT observations
- GRB 130508A: Swift detection of a probable burst
- GRB 130427A: Continued RATIR Optical and NIR Observations
- GRB 130427A, LBT optical spectrum
- GRB 130505B: Further Swift observations
- GRB 130504C: Swift-XRT afterglow confirmation
- GRB 130505A: MITSuME Akeno Optical observation
- GRB 130504C: Suzaku WAM observation of the prompt emission
- GRB 130504B: Suzaku WAM observation of the prompt emission
- GRB 130505A: Suzaku WAM observation of the prompt emission
- GRB 130427A, Watcher afterglow detection
- GRB 130427A: Excess optical emission consistent with an emerging supernova
- GRB 130427A: Amateur observations from Sweden
- GRB 130505A: RATIR Optical and NIR Observations
- GRB 130505B: Swift Candidate Afterglow
- GRB 130505A: Tautenburg afterglow observations
- GRB 130427A: Tautenburg afterglow observations
- Refined IPN Triangulation of GRB 130502B
- GRB 130427A: RHESSI observations
- GRB 130505A, Swift-BAT refined analysis
- GRB 130504C: further Swift-XRT observations
- Konus-Wind observation of GRB 130504C
- GRB 130505B: MAXI/GSC detection
- GRB 130505A: optical observations
- GRB 130504C: Swift-XRT observations
- GRB 130504C: Fermi GBM detection
- GRB 130427A: optical observations in CrAO
- GRB 130502A: optical upper limit
- GRB 130505A: E_iso record retraction
- GRB 130427A: correction to GCN 14487
- GRB 130505A: correction to GCN 14575
- GRB 130505A: Swift-XRT refined Analysis
- GRB 130505A: Largest E_iso ever measured
- Konus-Wind observation of GRB 130505A
- GRB 130504C: Fermi-LAT detection of a burst
- Swift/UVOT observations of GRB130505A
- GRB 130505A: iTelescope T12 optical observations
- GRB 130505A: Xinglong TNT optical observations
- GRB 130505A; Weihai optical observations
- GRB 130505A: Enhanced Swift-XRT position
- GRB 130505A: MITSuME Okayama Optical Observation
- GRB 130505A - Gemini-N/GMOS redshift determination
- GRB 130505A: MAXI/GSC detection
- Konus-Wind observation of GRB 130504B
- GRB 130504A: IAC80 optical candidate
- GRB 130505A: Swift detection of a burst with optical afterglow
- GRB 130504A: MITSuME Okayama upper limits
- IPN Triangulation of GRB 130504B
- GRB 130504B: Fermi GBM detection
- GRB 130504A: Bassano Bresciano Observatory optical upper limit
- GRB 130504A: Enhanced XRT position
- GRB 130502B: Suzaku WAM observation of the prompt emission
- GRB 130504A: Swift/UVOT Upper Limits
- GRB 130502B: Swift-XRT refined Analysis
- GRB 130504A, Swift-BAT refined analysis
- Swift-XRT X-ray afterglow candidate for GRB 130504A (BAT trigger 555096)
- GRB 130502B: possible TNG counterpart
- Trigger 555096: Swift detection of a possible burst
- GRB 130502A: Swift-BAT refined analysis
- GRB 130427A: Non-observation of VHE emission with HAWC
- GRB130502A: MASTER-Net optical observations
- GRB 130502A: Swift-XRT refined Analysis
- IPN Triangulation of GRB 130502B
- GRB 130502A: Fermi GBM detection
- GRB 130502B: Swift/UVOT Upper Limits
- GRB 130502A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB 130502B
- GRB 130502B: P60 Observations
- GRB 130502B Swift-XRT observations
- GRB 130502A: RATIR Optical and NIR Observations
- GRB 130427A: Pan-STARRS 1 optical observations
- GRB 130418A: TNG NIR observations
- GRB 130502A: Enhanced Swift-XRT position