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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"

18821 results found.

  1. GRB041224: Swift-BAT detection of a soft burst
  2. GRB041223: optical and NIR observations with REM
  3. Swift-BAT Time History of GRB041219
  4. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  5. GRB041223: ROTSE-III Optical Observations
  6. GRB041223: Swift-BAT detection of a bright long burst
  7. GRB041220: Swift-BAT burst
  8. GRB 041219 Optical Observations
  9. GRB041219c: Third Burst in One Day from Swift-BAT
  10. GRB041219b: A Swift-BAT burst
  11. Swift-BAT detection of the bright long burst GRB041219
  12. GRB041217: optical limit 30 min after GRB
  13. GRB041217: Optical Observations
  14. GRB041217: NIR and optical observations with REM
  15. GRB041217: P60 Optical Observations
  16. GRB041217: Infrared Observations
  17. GRB041217: The First GRB Located On-Board Swift
  18. GRB040916: Optical observations
  19. GRB040422: optical and NIR observations at the VLT
  20. GRB040223, improved XMM position
  21. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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Download all Circulars as a .tar.gz archive:
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