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"2983 results found.
- IPN Triangulation of GRB 140619C (long/very intense)
- GRB 140619A: Swift-BAT refined analysis
- Swift-BAT trigger 601928: Detection of a possible outburst from V490 Cep
- GRB 140606B / iPTF 14bfu: MOSFIRE NIR imaging
- IPN Triangulation of GRB 140606B
- IPN Triangulation of GRB 140528A
- GRB 140523A: NOT observation
- IPN Triangulation of GRB 140523A
- GRB 140523A: possible X-ray afterglow candidate from tiled Swift/XRT observations
- GRB 140516A: further Swift-XRT analysis
- GRB 140518A, Swift-BAT refined analysis
- GRB 140516A: Swift-BAT refined analysis
- GRB 140516A: Enhanced Swift-XRT position
- GRB 140516A: Swift detection of a short burst
- GRB 140515A: Swift-BAT refined analysis
- GRB 140512A: Mondy optical detection
- GRB 140509B: MAXI/GSC detection
- GRB 140430A: MITSuME Akeno upper limits
- GRB 140428A: Keck detection of a red optical afterglow candidate
- Swift trigger 593744: detection of a flare from UV Cet
- GRB 140320C: Mondy optical observations and afterglow confirmation
- GRB 140323A: Swift-BAT refined analysis
- GRB 140320C: Swift-XRT detection of the X-ray afterglow
- GRB 140320C: Mondy optical observations
- GRB 140320A: Fermi GBM observations suggest a short GRB
- GRB 140320A: Swift detection of a burst
- GRB 140311A: VLA Detection
- GRB 140311A: further NOT observations
- GRB 140311A: Kottamia I-band observation
- GRO J1744-28: Fermi GBM observation
- GRB 140311A: Enhanced Swift-XRT position
- GRB 140311A: Nanshan OT detection
- GRB 140305A: Swift-BAT refined analysis
- Konus-Wind observation of GRB 140226A
- IPN triangulation of GRB 140226A, a possible GRB counterpart to iPTF14yb
- GRB 140219A: results from Swift XRT and UVOT tiled observations
- GRB 140219A: MASTER before and after GRB observational arguments of the exceptionally Dark GRB
- Trigger 586482: Swift detection of GROJ1744-28
- GRB 140209A: Swift detection of a burst
- GRB 140206A, Swift-BAT refined analysis
- GRB 140129A: 5 GHz VLA observations
- GRB 140129B: MASTER OT early light curve
- GRB 140129A: CARMA early observations
- GRB 140129A, Swift-BAT refined analysis
- GRB 140114A: NOT afterglow observations
- GRB 140114A: KAIT Optical Upper Limit
- GRB 140114A: Enhanced Swift-XRT position
- GRB 140114A: Swift detection of a burst
- GRB 140110A: Swift/UVOT Observations
- GRB 131227A: Swift detection of a burst
- GRB 131225A: MASTER-Net optical observations
- GRB 131226A: Swift detection of a burst
- GRB 131215A: MAXI/GSC detection
- IPN Triangulation of GRB 131209A
- GRB 131127A: AROMA-N Optical Observation
- GRB 131122A (INTEGRAL trigger N6392): MASTER-NET optical observation
- IPN Triangulation of GRB 131118A
- GRB 131117A, Swift-BAT refined analysis
- IPN triangulation of GRB 131108A
- GRB 131030A: D50+BART detection and light curve optical decay
- GRB 131030A: Watcher OT detection
- GRB 131030A: Swift detection of a burst with an optical counterpart
- GRB 131004A: MOSFIRE NIR imaging
- GRB 131004A, Swift-BAT refined analysis
- GRB 131004A: Swift/UVOT Detection
- GRB 131004A: Enhanced Swift-XRT position
- GRB 131004A: optical afterglow from the NOT
- GRB 131004A: Swift detection of a burst (may be short)
- GRB 131002B, Swift-BAT refined analysis
- GRB 131001A, Swift-BAT refined analysis
- GRB 131002A: Faulkes Telescope North optical afterglow
- GRB 130925A: continuing Swift/XRT monitoring
- GRB 130925A Swift-BAT refined analysis
- GRB 130925A: Initial Similarities to Swift J1644+57
- GRB 130919A, Swift-BAT refined analysis
- GRB 130912A: Swift detection of a short burst
- GRB 130907A, Swift-BAT refined analysis
- GRB 130831A: Maidanak optical observations
- GRB 130821A: Swift-XRT observation
- GRB 130816B, Swift-BAT refined analysis
- GRB 130816B: GROND afterglow candidate
- GRB 130807A: Swift-XRT refined analysis
- GRB 130807A, Swift-BAT refined analysis
- GRB 130701A, Swift-BAT refined analysis
- GRB 130627B, Swift-BAT refined analysis
- GRB 130626A, Swift-BAT refined analysis
- GRB 130626A: Swift-XRT possible detection and UVOT upper limits
- GRB 130626A: Swift detection of a short burst
- Swift Trigger 558631 is not a real source
- GRB 130612A: Swift-BAT refined analysis
- GRB 130610A: CrAO optical observations
- GRB 130615A: Swift-BAT refined analysis
- GRB 130615A: Swift detection of a burst
- GRB 130610A: iTelescope T21 optical observations
- IPN Triangulation of GRB 130610B (long/multipeaked)
- GRB 130610A: Swift/UVOT Observations
- GRB 130610A: Skynet/PROMPT detection of the optical afterglow
- GRB 130610A - Liverpool Telescope Optical Afterglow Confirmation
- GRB 130610A: Swift detection of a burst with an optical counterpart
- GRB130606A: Montarrenti Observatory afterglow detection