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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"

12 results found.

  1. GRB 250917B: iTelescope T-26 upper limit
  2. GRB 250917B: Mondy and Zeiss-1000 SAO RAS optical observations, optical observations, afterglow candidate
  3. GRB 250917B: KAIT optical upper limit
  4. GRB 250917B: VLT/HAWK-I near-infrared observations
  5. GRB 250917B: Swift-BAT refined analysis
  6. GRB 250917B: Swift/UVOT Upper Limits
  7. GRB250917B: WFST optical observations
  8. GRB 250917B: Fermi GBM Observation
  9. GRB 250917B: Swift-XRT observations
  10. Fermi GRB 250917B: Global MASTER-Net observations report
  11. GRB 250917B: Swift detection of a short burst
  12. GRB 250917B: Fermi GBM Final Real-time Localization

Advanced

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