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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').
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. GRB 250306A: EIRSAT-1 GMOD detection
  2. Konus-Wind detection of GRB 250306A
  3. GRB 250306A: Swift-BAT refined analysis
  4. GRB 250306A: NuSTAR detection of the prompt emission
  5. GRB 250306A: AstroSat CZTI detection
  6. Swift GRB 250306A: Global MASTER-Net observations report
  7. GRB 250306A: Swift detection of a burst

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Download all Circulars as a .tar.gz archive:
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