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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"

24 results found.

  1. MeerKAT observation of GRB 191221B
  2. GRB 191221B: CALET Gamma-Ray Burst Monitor detection
  3. GRB 191221B: ATCA detection of the radio afterglow
  4. Konus-Wind observation of GRB 191221B
  5. GRB 191221B: Swift/UVOT Detection
  6. GRB 191221B: Insight-HXMT/HE detection
  7. GRB 191221B: AstroSat CZTI detection
  8. GRB 191221B: iTelescope T17 detection
  9. GRB 191221B: iTelescope optical observations
  10. GRB 191221B: ALMA detection
  11. GRB 191221B: Swift-BAT refined analysis
  12. GRB 191221B: Zadko observatory - Gingin optical observations
  13. GRB 191221B: LCO Optical Detection
  14. GRB 191221B: Swift-XRT refined Analysis
  15. GRB 191221B: MASTER VWFC OT yearly detection
  16. GRB 191221B: VLT/X-shooter redshift
  17. GRB 191221B: Correction to GCN26551 - VIRT OT observation
  18. GRB 191221B: VIRT Optical Upper Limits
  19. GRB 191221B: AGILE/MCAL observations
  20. GRB 191221B: Enhanced Swift-XRT position
  21. GRB 191221B: Swift/UVOT redshift
  22. GRB 191221B: MASTER OT detection
  23. Swift GRB 191221B: Global MASTER-Net observations report
  24. GRB 191221B: Swift detection of a burst and a very bright optical candidate

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Download all Circulars as a .tar.gz archive:
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