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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"

19530 results found.

  1. GRB041228: Swift-BAT detection of a burst
  2. GRB041219; RXTE ASM Observations
  3. NIR Observations of GRB 041219
  4. GRB041226: ROTSE-III Optical Observations
  5. GRB041226: Swift-BAT detection of a burst
  6. GRB041223: decay of the afterglow
  7. GRB041224: ROTSE-III Optical Observations
  8. GRB 041223: XRT afterglow spectrum and light curve
  9. GRB 041223 Fluence measured by Swift-BAT
  10. GRB041224: Swift-BAT detection of a soft burst
  11. GRB041223: optical and NIR observations with REM
  12. Swift-BAT Time History of GRB041219
  13. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  14. GRB041223: ROTSE-III Optical Observations
  15. GRB041223: Swift-BAT detection of a bright long burst
  16. GRB041220: Swift-BAT burst
  17. GRB 041219 Optical Observations
  18. GRB041219c: Third Burst in One Day from Swift-BAT
  19. GRB041219b: A Swift-BAT burst
  20. Swift-BAT detection of the bright long burst GRB041219
  21. GRB041217: optical limit 30 min after GRB
  22. GRB041217: Optical Observations
  23. GRB041217: NIR and optical observations with REM
  24. GRB041217: P60 Optical Observations
  25. GRB041217: Infrared Observations
  26. GRB041217: The First GRB Located On-Board Swift
  27. GRB040916: Optical observations
  28. GRB040422: optical and NIR observations at the VLT
  29. GRB040223, improved XMM position
  30. 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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