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"15 results found.
- GRB 250706B/C: Insight-HXMT detection
- IPN triangulation of GRB 250706C (consistent with the GRB 250706B)
- GRB 250706B/C: Konus-Wind analysis of the prompt emission
- GRB 250706B: SVOM observations interpreted as the afterglow of GRB 250706C
- GRB 250706B/C: VLT/X-shooter redshift z = 0.942
- GRB 250706B/C: Fermi-LAT detection
- GRB 250706B: Swift/UVOT Detection
- GRB 250706C: Konus-Wind detection of a very bright GRB ~1200 s before GRB 250706B
- GRB 250706B: refined SVOM/MXT data analysis
- GRB 250706B: REM optical observations
- GRB250706B: Swift-XRT counterpart detection
- GRB 250706B: iTelescope optical observations
- GRB 250706B: SVOM/VT optical observation
- GRB 250706B: TRT bright optical counterpart detection
- GRB 250706B: SVOM detection of a long burst