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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"

19243 results found.

  1. GRB 050117, I-band observations
  2. GRB 050117: Optical observation
  3. GRB050117: Refined XRT position
  4. GRB050117: MASTER optical observations
  5. MASTER:GRB050117 SWIFT
  6. GRB050117: Swift-BAT detection of a long multi-peaked burst
  7. GRB050117: Swift XRT Position
  8. SGR1806-20: Swift-BAT observations of two additional bursts
  9. SGR 1806-20, RHESSI observations of the 041227 giant flare
  10. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  11. GRB 041217: Optical observations
  12. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  13. GRB041228: ROTSE-III Optical Observations
  14. GRB041228: Swift-BAT detection of a burst
  15. GRB041219; RXTE ASM Observations
  16. NIR Observations of GRB 041219
  17. GRB041226: ROTSE-III Optical Observations
  18. GRB041226: Swift-BAT detection of a burst
  19. GRB041223: decay of the afterglow
  20. GRB041224: ROTSE-III Optical Observations
  21. GRB 041223: XRT afterglow spectrum and light curve
  22. GRB 041223 Fluence measured by Swift-BAT
  23. GRB041224: Swift-BAT detection of a soft burst
  24. GRB041223: optical and NIR observations with REM
  25. Swift-BAT Time History of GRB041219
  26. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  27. GRB041223: ROTSE-III Optical Observations
  28. GRB041223: Swift-BAT detection of a bright long burst
  29. GRB041220: Swift-BAT burst
  30. GRB 041219 Optical Observations
  31. GRB041219c: Third Burst in One Day from Swift-BAT
  32. GRB041219b: A Swift-BAT burst
  33. Swift-BAT detection of the bright long burst GRB041219
  34. GRB041217: optical limit 30 min after GRB
  35. GRB041217: Optical Observations
  36. GRB041217: NIR and optical observations with REM
  37. GRB041217: P60 Optical Observations
  38. GRB041217: Infrared Observations
  39. GRB041217: The First GRB Located On-Board Swift
  40. GRB040916: Optical observations
  41. GRB040422: optical and NIR observations at the VLT
  42. GRB040223, improved XMM position
  43. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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