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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"

18632 results found.

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

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