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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"

26 results found.

  1. GRB 210619B: Ondrejov D50 detection
  2. GRB 210420B: Assy optical observations
  3. GRB 210420B: follow-up photometry of optical afterglow at INASAN/Simeiz
  4. GRB 210420B: Zeiss-1000 of Koshka optical observations
  5. GRB 210420B: continued Tautenburg observations
  6. GRB 210420B: Correction to AST3-3 YaoAn magnitude
  7. GRB 210420B: follow-up photometry of the optical afterglow at Konkoly
  8. GRB 210420B: Swift-BAT refined analysis
  9. GRB 210420B: Swift-XRT refined Analysis
  10. GRB 210420B: Montarrenti Observatory follow-up observations
  11. GRB 210420B: Correction to DDOTI Magnitude
  12. GRB 210420B: Ondrejov D50 optical afterglow detection
  13. GRB 210420B: RATIR Optical and NIR Observations
  14. GRB 210420B: Tautenburg observations
  15. GRB 210420B: Swift/UVOT Detection
  16. GRB 210420B: KAIT Optical Observations
  17. GRB 210420B: DDOTI Detection of the Afterglow
  18. GRB 210420B: update on the BAT trigger time
  19. GRB 210420B: Redshift from GTC
  20. GRB 210420B: Multiband photometry from NOT
  21. GRB 210420B: Montarrenti Observatory optical afterglow detection
  22. GRB 210420B: AST3-3 YaoAn Optical Observation
  23. GRB 210420B: BOOTES-4/MET optical afterglow detection
  24. GRB 210420B: Optical observations
  25. GRB 210420B: MASTER optical counterpart detection
  26. GRB 210420B: Swift detection of a burst

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Download all Circulars as a .tar.gz archive:
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