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"5544 results found.
- GRB 110212A: Swift detection of a burst
- GRB 110201A: optical observations
- GRB 110210A: Swift detection of a burst
- GRB 110205A : HCT optical observations
- GRB 110206A: GROND detection of afterglow candidate
- GRB 110206A: UVOT detection of afterglow candidate
- GRB 110205A: Lightbuckets Optical Observations
- GRB 110205A: Newcastle Observatory Optical Observations
- GRB110201A: MITSuME Okayama optical upper limits
- GRB 110201A: MASTER optical observations
- GRB 110201A: Swift detection of a burst
- Swift Trigger 442539 is probably not a GRB
- GRB 110112A: MITSuME Akeno and Okayama optical upper limits
- GRB 110102A: Swift detection of a burst with an optical detection
- GRB101224A: MITSuME Okayama optical upper limits
- XRF 101117A, RIMOTS optical upper limits
- Konus-Wind observation of GRB 101130A
- IPN Localization of GRB101130 (possible short duration burst)
- GRB 101030A: Swift detection of a burst
- GRB 101020A: Swift detection of a burst
- GRB 101017A: Swift detection of a burst with optical counterpart
- Swift Trigger 435520 is probably not a GRB
- GRB 100925A / MAXI J1659-152: MASTER optical observations
- GRB 100925A / MAXI J1659-152: Optical observation with the Kottamia 188cm telescope
- GRB100925A/MAXI J1659-152 MITSuME Ishigakijima and Okayama Optical Observation
- MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
- GRB 100909A: Faulkes Telescope North afterglow candidate
- GRB 100909A: a long GRB detected by INTEGRAL
- GRB100906A: detection at 15GHz
- GRB100901A: IAO optical upper limits at 4 days after the burst
- GRB 100906A: GRAS-007 optical observations
- GRB100906A: R band observations
- GRB100906A: Optical observations at IAO
- GRB100906A: MITSuME Okayama Optical Observation
- GRB 100906A: Ondrejov 65cm observations
- GRB 100901A: ISON-NM optical observations
- GRB100905A: Optical upper limits at IAO
- GRB100905A: MITSuME Okayama optical upper limits
- GRB 100905A: MASTER Prompt Optical Observations
- GRB 100905A: Swift detection of a burst
- GRB10901A: Murikabushi telescope observation at 3 days after the burst
- GRB100902A: Optical upper limits at IAO
- GRB10901A: Optical observations at IAO
- IPN Triangulation of the very bright GRB 100829A
- GRB 100901A: HCT optical observations
- GRB 100901A: Kanata Telescope observation of the optical afterglow
- GRB100901A: MITSuME Okayama Optical Observation at 1 day after the burst
- GRB 100901A: ISON-NM optical observations
- GRB 100901A : HCT optical observations
- GRB 100901A: THO optical observations
- GRB100901A: MITSuME Okayama Optical Observation
- GRB 100901A: optical observation at Mt.Terskol
- GRB 100814A: ISON-NM optical observations
- GRB 100814A : Liverpool Telescope Observations
- GRB 100814A : Lulin optical observation
- GRB 100816A : Lulin r'-band observation
- GRB 100814A: CQUEAN r- and i-band Observation
- GRB 100814A: Swift detection of a burst with an optical afterglow
- GRB 100807A: P200 Infrared Observations
- GRB 100807A: P60 Optical Afterglow Discovery
- GRB 100807A: ROTSE-III Optical Limits
- GRB 100807A: Swift detection of a burst
- GRB 100802A: NOT optical observation
- GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
- GRB 100802A: Swift detection of a burst
- GRB 100728A: GROND Detection of the NIR Afterglow Candidate
- GRB 100727A: Swift detection of a burst
- GRB 100725B: Swift detection of a burst
- GRB 100725A: Swift detection of a burst
- GRB 100724A, GROND detection of an afterglow candidate
- Fermi GBM trigger 300370702 (100709513) is not a GRB
- GRB 100704A: Swift detection of a burst
- GRB 100526A: Gemini/NIRI afterglow confirmation and host galaxy
- GRB100625A: GROND confirmation of constant source
- GRB 100625A Gemini-South 2nd epoch imaging
- GRB 100621A MOA-II optical limit
- GRB 100621A: VLT/X-shooter redshift
- GRB 100621A: ROTSE-III Optical Limits
- GRB 100615A: Swift detection of a burst
- GRB 100606A: Swift detection of a burst
- GRB100526B: GROND Upper limits
- GRB 100526A: Swift detection of a burst
- GRB 100522A: GROND observations, upper limits
- GRB 100522A: Swift detection of a burst
- GRB 100518A: GROND afterglow observation and photo-z
- GRB 100514A: optical afterglow confirmation
- GRB 100514A: Enhanced Swift-XRT position
- GRB 100514A: Swift detection of a burst
- GRB 100513A: Swift detection of a burst
- GRB 100510A: MAXI/GSC detection
- GRB 100508A: ROTSE-III Optical Limits
- GRB 100508A: Swift detection of a burst
- An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
- GRB 100503A: Fermi GBM detection
- GRB 100504A: Swift detection of a burst
- Trigger 421072: Possible Swift detection of a GRB or transient
- GRB 100423A: CrAO optical observations
- GRB 100425A: Swift detection of a burst
- GRB 100424A: Swift detection of a burst
- GRB 100420A: GRT Optical Observation