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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').

17084 results found.

  1. GRB 050215b: Swift XRT Source Variability
  2. GRB 050215B: candidate afterglow
  3. GRB 050215b : Lulin follow-up observation
  4. GRB 050215b, BOOTES-2 simultaneous optical observations
  5. GRB 050215B: UKIRT K-band imaging
  6. GRB 050215b: Swift XRT Observations
  7. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  8. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  9. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  10. GRB050215B: ROTSE-III optical observations
  11. GRB050215A: ROTSE-III Optical Observations
  12. short/hard GRB 050202, optical observations
  13. GRB 050128: Radio observations
  14. Further analysis of the short Swift-BAT GRB 050202
  15. GRB 050202: Second epoch radio observations
  16. GRB050202: Radio Observations
  17. GRB 050202: Short burst detected by Swift-BAT
  18. SGR1806-20: Swift-BAT detection of a large normal burst
  19. GRB050128: Faulkes Telescope South observations
  20. GRB050128,optical observations
  21. GRB050126: Updated Swift XRT Position
  22. GRB 050126: Radio Observations
  23. GRB050128 Swift-BAT observations
  24. GRB 050128: Swift XRT prompt afterglow position
  25. GRB 050124: K-band afterglow observations
  26. GRB050126: MASTER optical limit for KECK OT
  27. GRB050126: Burst Parameters Measured by BAT
  28. GRB050126: MASTER optical observations
  29. GRB 050126: Prompt XRT detection and localization
  30. GRB050124: No Swift UVOT Detection of Afterglow Emission
  31. GRB 050117a: Radio Observations
  32. GRB050124,optical observation
  33. GRB050124: Updated Swift XRT Position and Fluxes
  34. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  35. GRB050124: Refined BAT position, spectral and fluence information
  36. GRB050124: Swift-BAT position of a double-peaked burst
  37. GRB050117a: Radio Observations
  38. GRB050117a: Refined analysis
  39. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  40. GRB050117b: Swift-BAT detection of a weak burst
  41. GRB050117: optical observation
  42. GRB 050117, I-band observations
  43. GRB 050117: Optical observation
  44. GRB050117: Refined XRT position
  45. GRB050117: MASTER optical observations
  46. MASTER:GRB050117 SWIFT
  47. GRB050117: Swift-BAT detection of a long multi-peaked burst
  48. GRB050117: Swift XRT Position
  49. SGR1806-20: Swift-BAT observations of two additional bursts
  50. SGR 1806-20, RHESSI observations of the 041227 giant flare
  51. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  52. GRB 041217: Optical observations
  53. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  54. GRB041228: ROTSE-III Optical Observations
  55. GRB041228: Swift-BAT detection of a burst
  56. GRB041219; RXTE ASM Observations
  57. NIR Observations of GRB 041219
  58. GRB041226: ROTSE-III Optical Observations
  59. GRB041226: Swift-BAT detection of a burst
  60. GRB041223: decay of the afterglow
  61. GRB041224: ROTSE-III Optical Observations
  62. GRB 041223: XRT afterglow spectrum and light curve
  63. GRB 041223 Fluence measured by Swift-BAT
  64. GRB041224: Swift-BAT detection of a soft burst
  65. GRB041223: optical and NIR observations with REM
  66. Swift-BAT Time History of GRB041219
  67. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  68. GRB041223: ROTSE-III Optical Observations
  69. GRB041223: Swift-BAT detection of a bright long burst
  70. GRB041220: Swift-BAT burst
  71. GRB 041219 Optical Observations
  72. GRB041219c: Third Burst in One Day from Swift-BAT
  73. GRB041219b: A Swift-BAT burst
  74. Swift-BAT detection of the bright long burst GRB041219
  75. GRB041217: optical limit 30 min after GRB
  76. GRB041217: Optical Observations
  77. GRB041217: NIR and optical observations with REM
  78. GRB041217: P60 Optical Observations
  79. GRB041217: Infrared Observations
  80. GRB041217: The First GRB Located On-Board Swift
  81. GRB040916: Optical observations
  82. GRB040422: optical and NIR observations at the VLT
  83. GRB040223, improved XMM position
  84. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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