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"9 results found.
- GRB 250206A: VZLUSAT-2 detection
- GRB 250206A: Fermi GBM Observation
- Konus-Wind detection of GRB 250206A
- GRB 250206A: Swift-XRT observations
- GRB 250206A: Tiled Swift observations
- GRB 250206A: EIRSAT-1 GMOD Detection
- GRB 250206A: Fermi-LAT detection
- GRB 250206A: BALROG localization (Fermi Trigger 760564296 / GRB 250206827)
- GRB 250206A: Fermi GBM Final Real-time Localization