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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"

11 results found.

  1. GRB 250912A: SVOM/ECLAIRs refined analysis
  2. GRB 250912A: Swift/BAT-GUANO localization skymap of a possibly short burst
  3. GRB 250912A: SVOM/COLIBRÍ (FM-GFT) optical observations
  4. GRB 250912A: Swift-XRT observations
  5. GRB 250912A: VLT observations
  6. GRB 250912A: Fermi GBM Observation
  7. GRB 250912A: SVOM/GRM analysis suggests a possible short GRB with extended emission
  8. GRB 250912A: LCO optical upper limit
  9. Fermi GRB 250912A: Global MASTER-Net observations report
  10. GRB 250912A: SVOM detection of a burst
  11. GRB 250912A: Fermi GBM Final Real-time Localization

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
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Get involved on GitHub.

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