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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"

19271 results found.

  1. Further analysis of the short Swift-BAT GRB 050202
  2. GRB 050202: Second epoch radio observations
  3. GRB050202: Radio Observations
  4. GRB 050202: Short burst detected by Swift-BAT
  5. SGR1806-20: Swift-BAT detection of a large normal burst
  6. GRB050128: Faulkes Telescope South observations
  7. GRB050128,optical observations
  8. GRB050126: Updated Swift XRT Position
  9. GRB 050126: Radio Observations
  10. GRB050128 Swift-BAT observations
  11. GRB 050128: Swift XRT prompt afterglow position
  12. GRB 050124: K-band afterglow observations
  13. GRB050126: MASTER optical limit for KECK OT
  14. GRB050126: Burst Parameters Measured by BAT
  15. GRB050126: MASTER optical observations
  16. GRB 050126: Prompt XRT detection and localization
  17. GRB050124: No Swift UVOT Detection of Afterglow Emission
  18. GRB 050117a: Radio Observations
  19. GRB050124,optical observation
  20. GRB050124: Updated Swift XRT Position and Fluxes
  21. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  22. GRB050124: Refined BAT position, spectral and fluence information
  23. GRB050124: Swift-BAT position of a double-peaked burst
  24. GRB050117a: Radio Observations
  25. GRB050117a: Refined analysis
  26. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  27. GRB050117b: Swift-BAT detection of a weak burst
  28. GRB050117: optical observation
  29. GRB 050117, I-band observations
  30. GRB 050117: Optical observation
  31. GRB050117: Refined XRT position
  32. GRB050117: MASTER optical observations
  33. MASTER:GRB050117 SWIFT
  34. GRB050117: Swift-BAT detection of a long multi-peaked burst
  35. GRB050117: Swift XRT Position
  36. SGR1806-20: Swift-BAT observations of two additional bursts
  37. SGR 1806-20, RHESSI observations of the 041227 giant flare
  38. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  39. GRB 041217: Optical observations
  40. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  41. GRB041228: ROTSE-III Optical Observations
  42. GRB041228: Swift-BAT detection of a burst
  43. GRB041219; RXTE ASM Observations
  44. NIR Observations of GRB 041219
  45. GRB041226: ROTSE-III Optical Observations
  46. GRB041226: Swift-BAT detection of a burst
  47. GRB041223: decay of the afterglow
  48. GRB041224: ROTSE-III Optical Observations
  49. GRB 041223: XRT afterglow spectrum and light curve
  50. GRB 041223 Fluence measured by Swift-BAT
  51. GRB041224: Swift-BAT detection of a soft burst
  52. GRB041223: optical and NIR observations with REM
  53. Swift-BAT Time History of GRB041219
  54. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  55. GRB041223: ROTSE-III Optical Observations
  56. GRB041223: Swift-BAT detection of a bright long burst
  57. GRB041220: Swift-BAT burst
  58. GRB 041219 Optical Observations
  59. GRB041219c: Third Burst in One Day from Swift-BAT
  60. GRB041219b: A Swift-BAT burst
  61. Swift-BAT detection of the bright long burst GRB041219
  62. GRB041217: optical limit 30 min after GRB
  63. GRB041217: Optical Observations
  64. GRB041217: NIR and optical observations with REM
  65. GRB041217: P60 Optical Observations
  66. GRB041217: Infrared Observations
  67. GRB041217: The First GRB Located On-Board Swift
  68. GRB040916: Optical observations
  69. GRB040422: optical and NIR observations at the VLT
  70. GRB040223, improved XMM position
  71. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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