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 250530A: SVOM/GRM analysis
- GRB 250530A: VLT/HAWK-I NIR counterpart fading
- GRB 250530A: TNG detection of a NIR source inside the Swift/XRT error circle
- GRB 250530A: EP-FXT counterpart detection
- GRB 250530A: SVOM/VT optical upper limit
- GRB 250530A: Swift-XRT counterpart detection
- GRB 250530A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate retraction and detection limit
- GRB 250530A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
- GRB 250530A: SVOM detection of a burst