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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

25 results found.

  1. GRB 210306A: LBT observations of the likely host galaxy
  2. GRB 210306A: GIT optical follow-up
  3. GRB 210306A: HCT optical upper limit
  4. GRB 210306A: LBT observations
  5. GRB 210306A: Tautenburg observations
  6. Konus-Wind detection of GRB 210306A
  7. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  8. GRB 210306A: Swift/UVOT Detection
  9. GRB 210306A: continued Mondy optical observations
  10. GRB 210306A: Swift-XRT refined Analysis
  11. GRB 210306A: continued Mondy optical observations
  12. GRB 210306A: 1.3m DFOT observations
  13. GRB 210306A: Swift-BAT refined analysis
  14. GRB 210306A: Mondy optical observations
  15. GRB 210306A: MITSuME Akeno optical observation
  16. GRB 210306A: NEXT optical observations
  17. Swift GRB 210306A: Global MASTER-Net observations report
  18. GRB 210306A: Fermi GBM observation
  19. GRB 210306A: Tautenburg observations
  20. GRB 210306A: iTelescope T24 optical observations
  21. GRB 210306A: Fermi-LAT detection
  22. GRB 210306A: LCO Optical Afterglow Detection
  23. GRB 210306A: iTelescope optical afterglow observations
  24. GRB 210306A: DDOTI Afterglow Confirmation
  25. GRB 210306A: Swift detection of a burst with a bright optical counterpart

Advanced

Download all Circulars as a .tar.gz archive:
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