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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').

17110 results found.

  1. GRB 050306: Swift-BAT detection of a long burst
  2. GRB050215B: Late-Time Swift UVOT Observations
  3. PROMPT VRcIc Observations of GRB 050223
  4. GRB 050223: optical observations
  5. GRB050223 XMM-Newton observation
  6. INTEGRAL detection of GRB 050223
  7. GRB050223: No Swift UVOT Detection of Afterglow Emission
  8. GRB050223: ROTSE-III Optical Observations
  9. GRB 050223 Swift/BAT detection of a burst
  10. GRB 050223: Swift XRT Position
  11. GRB050219b: CORRECTION to time of UVOT observations
  12. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  13. GRB 050219b: CORRECTION to refined XRT position
  14. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  15. GRB 050219b: Refined XRT position
  16. GRB 050219b: Swift-BAT detection of a burst
  17. GRB 050219b: CORRECTION: Swift XRT Position
  18. GRB 050219b: Swift XRT Position
  19. GRB 050219a, optical observations
  20. GRB 050219a: Refined XRT position
  21. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  22. GRB 050219: Swift-BAT detection of a burst
  23. GRB050215b: Swift UVOT Detection of Afterglow Emission
  24. GRB 050219: Prompt X-ray position
  25. GRB 050215b: XRT confirmation of IR afterglow candidate
  26. GRB050215b: P60 Optical Observations
  27. GRB 050215b: Swift XRT Source Variability
  28. GRB 050215B: candidate afterglow
  29. GRB 050215b : Lulin follow-up observation
  30. GRB 050215b, BOOTES-2 simultaneous optical observations
  31. GRB 050215B: UKIRT K-band imaging
  32. GRB 050215b: Swift XRT Observations
  33. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  34. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  35. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  36. GRB050215B: ROTSE-III optical observations
  37. GRB050215A: ROTSE-III Optical Observations
  38. short/hard GRB 050202, optical observations
  39. GRB 050128: Radio observations
  40. Further analysis of the short Swift-BAT GRB 050202
  41. GRB 050202: Second epoch radio observations
  42. GRB050202: Radio Observations
  43. GRB 050202: Short burst detected by Swift-BAT
  44. SGR1806-20: Swift-BAT detection of a large normal burst
  45. GRB050128: Faulkes Telescope South observations
  46. GRB050128,optical observations
  47. GRB050126: Updated Swift XRT Position
  48. GRB 050126: Radio Observations
  49. GRB050128 Swift-BAT observations
  50. GRB 050128: Swift XRT prompt afterglow position
  51. GRB 050124: K-band afterglow observations
  52. GRB050126: MASTER optical limit for KECK OT
  53. GRB050126: Burst Parameters Measured by BAT
  54. GRB050126: MASTER optical observations
  55. GRB 050126: Prompt XRT detection and localization
  56. GRB050124: No Swift UVOT Detection of Afterglow Emission
  57. GRB 050117a: Radio Observations
  58. GRB050124,optical observation
  59. GRB050124: Updated Swift XRT Position and Fluxes
  60. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  61. GRB050124: Refined BAT position, spectral and fluence information
  62. GRB050124: Swift-BAT position of a double-peaked burst
  63. GRB050117a: Radio Observations
  64. GRB050117a: Refined analysis
  65. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  66. GRB050117b: Swift-BAT detection of a weak burst
  67. GRB050117: optical observation
  68. GRB 050117, I-band observations
  69. GRB 050117: Optical observation
  70. GRB050117: Refined XRT position
  71. GRB050117: MASTER optical observations
  72. MASTER:GRB050117 SWIFT
  73. GRB050117: Swift-BAT detection of a long multi-peaked burst
  74. GRB050117: Swift XRT Position
  75. SGR1806-20: Swift-BAT observations of two additional bursts
  76. SGR 1806-20, RHESSI observations of the 041227 giant flare
  77. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  78. GRB 041217: Optical observations
  79. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  80. GRB041228: ROTSE-III Optical Observations
  81. GRB041228: Swift-BAT detection of a burst
  82. GRB041219; RXTE ASM Observations
  83. NIR Observations of GRB 041219
  84. GRB041226: ROTSE-III Optical Observations
  85. GRB041226: Swift-BAT detection of a burst
  86. GRB041223: decay of the afterglow
  87. GRB041224: ROTSE-III Optical Observations
  88. GRB 041223: XRT afterglow spectrum and light curve
  89. GRB 041223 Fluence measured by Swift-BAT
  90. GRB041224: Swift-BAT detection of a soft burst
  91. GRB041223: optical and NIR observations with REM
  92. Swift-BAT Time History of GRB041219
  93. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  94. GRB041223: ROTSE-III Optical Observations
  95. GRB041223: Swift-BAT detection of a bright long burst
  96. GRB041220: Swift-BAT burst
  97. GRB 041219 Optical Observations
  98. GRB041219c: Third Burst in One Day from Swift-BAT
  99. GRB041219b: A Swift-BAT burst
  100. Swift-BAT detection of the bright long burst GRB041219

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