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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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').
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"

7 results found.

  1. Fermi GRB 250808A: Global MASTER-Net observations report
  2. GRB 250808A: VLT X-shooter candidate counterpart
  3. GRB 250808A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  4. GRB 250808A: Fermi GBM Observation
  5. GRB 250808A: Swift-XRT candidate counterpart detection
  6. GRB 250808A: SVOM detection of a long burst
  7. GRB 250808A: Fermi GBM Final Real-time Localization

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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