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"17 results found.
- GRB 250818B: MeerKAT Detection
- GRB 250818B: 10 GHz VLA detection
- GRB 250818B: FTW optical and NIR observations show reddening of the counterpart
- GRB 250818B: Kilonova-Catcher optical afterglow detection
- GRB 250818B: Liverpool Telescope optical detections
- GRB 250818B: Swift/UVOT Detection
- GRB 250818B: optical afterglow detection with Lesedi (GOTO25fzq)
- GRB 250818B: TRT Optical Observation
- GRB 250818B: SAO RAS optical observations
- GRB 250818B: NOT optical observations
- GRB 250818B: EP-FXT counterpart detection
- GRB 250818B: Keck redshift of the optical afterglow
- GRB 250818B: KAIT optical observations
- GRB 250818B: SVOM/VT optical observation
- GRB 250818B: Swift-XRT afterglow detection
- GRB 250818B: GOTO optical counterpart candidate
- GRB 250818B: SVOM detection of a short burst