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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"

13 results found.

  1. GRB 250327A: Swift/UVOT Upper Limits
  2. GRB 250327A Swift-BAT refined analysis
  3. GRB 250327A: SVOM/VT upper limits on the XRT position
  4. GRB 250327A: Swift-XRT refined Analysis
  5. GRB 250327A: J-band observations with WINTER
  6. GRB 250327A: SVOM/VT optical candidate
  7. GRB 250327A: Fermi GBM observation
  8. Fermi GRB 250327A: Global MASTER-Net observations report
  9. Swift GRB 250327A: Global MASTER-Net observations report
  10. GRB 250327A: DDOTI Optical Observations
  11. GRB 250327A: COLIBRÍ optical upper limit
  12. GRB 250327A: Swift detection of a burst
  13. GRB 250327A: Fermi GBM Final Real-time Localization

Advanced

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