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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"

18648 results found.

  1. GRB050117a: Radio Observations
  2. GRB050117a: Refined analysis
  3. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  4. GRB050117b: Swift-BAT detection of a weak burst
  5. GRB050117: optical observation
  6. GRB 050117, I-band observations
  7. GRB 050117: Optical observation
  8. GRB050117: Refined XRT position
  9. GRB050117: MASTER optical observations
  10. MASTER:GRB050117 SWIFT
  11. GRB050117: Swift-BAT detection of a long multi-peaked burst
  12. GRB050117: Swift XRT Position
  13. SGR1806-20: Swift-BAT observations of two additional bursts
  14. SGR 1806-20, RHESSI observations of the 041227 giant flare
  15. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  16. GRB 041217: Optical observations
  17. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  18. GRB041228: ROTSE-III Optical Observations
  19. GRB041228: Swift-BAT detection of a burst
  20. GRB041219; RXTE ASM Observations
  21. NIR Observations of GRB 041219
  22. GRB041226: ROTSE-III Optical Observations
  23. GRB041226: Swift-BAT detection of a burst
  24. GRB041223: decay of the afterglow
  25. GRB041224: ROTSE-III Optical Observations
  26. GRB 041223: XRT afterglow spectrum and light curve
  27. GRB 041223 Fluence measured by Swift-BAT
  28. GRB041224: Swift-BAT detection of a soft burst
  29. GRB041223: optical and NIR observations with REM
  30. Swift-BAT Time History of GRB041219
  31. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  32. GRB041223: ROTSE-III Optical Observations
  33. GRB041223: Swift-BAT detection of a bright long burst
  34. GRB041220: Swift-BAT burst
  35. GRB 041219 Optical Observations
  36. GRB041219c: Third Burst in One Day from Swift-BAT
  37. GRB041219b: A Swift-BAT burst
  38. Swift-BAT detection of the bright long burst GRB041219
  39. GRB041217: optical limit 30 min after GRB
  40. GRB041217: Optical Observations
  41. GRB041217: NIR and optical observations with REM
  42. GRB041217: P60 Optical Observations
  43. GRB041217: Infrared Observations
  44. GRB041217: The First GRB Located On-Board Swift
  45. GRB040916: Optical observations
  46. GRB040422: optical and NIR observations at the VLT
  47. GRB040223, improved XMM position
  48. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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