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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"

19335 results found.

  1. SGR 1806-20, RHESSI observations of the 041227 giant flare
  2. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  3. GRB 041217: Optical observations
  4. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  5. GRB041228: ROTSE-III Optical Observations
  6. GRB041228: Swift-BAT detection of a burst
  7. GRB041219; RXTE ASM Observations
  8. NIR Observations of GRB 041219
  9. GRB041226: ROTSE-III Optical Observations
  10. GRB041226: Swift-BAT detection of a burst
  11. GRB041223: decay of the afterglow
  12. GRB041224: ROTSE-III Optical Observations
  13. GRB 041223: XRT afterglow spectrum and light curve
  14. GRB 041223 Fluence measured by Swift-BAT
  15. GRB041224: Swift-BAT detection of a soft burst
  16. GRB041223: optical and NIR observations with REM
  17. Swift-BAT Time History of GRB041219
  18. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  19. GRB041223: ROTSE-III Optical Observations
  20. GRB041223: Swift-BAT detection of a bright long burst
  21. GRB041220: Swift-BAT burst
  22. GRB 041219 Optical Observations
  23. GRB041219c: Third Burst in One Day from Swift-BAT
  24. GRB041219b: A Swift-BAT burst
  25. Swift-BAT detection of the bright long burst GRB041219
  26. GRB041217: optical limit 30 min after GRB
  27. GRB041217: Optical Observations
  28. GRB041217: NIR and optical observations with REM
  29. GRB041217: P60 Optical Observations
  30. GRB041217: Infrared Observations
  31. GRB041217: The First GRB Located On-Board Swift
  32. GRB040916: Optical observations
  33. GRB040422: optical and NIR observations at the VLT
  34. GRB040223, improved XMM position
  35. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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