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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').

18306 results found.

  1. INTEGRAL detection of GRB 050223
  2. GRB050223: No Swift UVOT Detection of Afterglow Emission
  3. GRB050223: ROTSE-III Optical Observations
  4. GRB 050223 Swift/BAT detection of a burst
  5. GRB 050223: Swift XRT Position
  6. GRB050219b: CORRECTION to time of UVOT observations
  7. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  8. GRB 050219b: CORRECTION to refined XRT position
  9. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  10. GRB 050219b: Refined XRT position
  11. GRB 050219b: Swift-BAT detection of a burst
  12. GRB 050219b: CORRECTION: Swift XRT Position
  13. GRB 050219b: Swift XRT Position
  14. GRB 050219a, optical observations
  15. GRB 050219a: Refined XRT position
  16. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  17. GRB 050219: Swift-BAT detection of a burst
  18. GRB050215b: Swift UVOT Detection of Afterglow Emission
  19. GRB 050219: Prompt X-ray position
  20. GRB 050215b: XRT confirmation of IR afterglow candidate
  21. GRB050215b: P60 Optical Observations
  22. GRB 050215b: Swift XRT Source Variability
  23. GRB 050215B: candidate afterglow
  24. GRB 050215b : Lulin follow-up observation
  25. GRB 050215b, BOOTES-2 simultaneous optical observations
  26. GRB 050215B: UKIRT K-band imaging
  27. GRB 050215b: Swift XRT Observations
  28. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  29. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  30. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  31. GRB050215B: ROTSE-III optical observations
  32. GRB050215A: ROTSE-III Optical Observations
  33. short/hard GRB 050202, optical observations
  34. GRB 050128: Radio observations
  35. Further analysis of the short Swift-BAT GRB 050202
  36. GRB 050202: Second epoch radio observations
  37. GRB050202: Radio Observations
  38. GRB 050202: Short burst detected by Swift-BAT
  39. SGR1806-20: Swift-BAT detection of a large normal burst
  40. GRB050128: Faulkes Telescope South observations
  41. GRB050128,optical observations
  42. GRB050126: Updated Swift XRT Position
  43. GRB 050126: Radio Observations
  44. GRB050128 Swift-BAT observations
  45. GRB 050128: Swift XRT prompt afterglow position
  46. GRB 050124: K-band afterglow observations
  47. GRB050126: MASTER optical limit for KECK OT
  48. GRB050126: Burst Parameters Measured by BAT
  49. GRB050126: MASTER optical observations
  50. GRB 050126: Prompt XRT detection and localization
  51. GRB050124: No Swift UVOT Detection of Afterglow Emission
  52. GRB 050117a: Radio Observations
  53. GRB050124,optical observation
  54. GRB050124: Updated Swift XRT Position and Fluxes
  55. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  56. GRB050124: Refined BAT position, spectral and fluence information
  57. GRB050124: Swift-BAT position of a double-peaked burst
  58. GRB050117a: Radio Observations
  59. GRB050117a: Refined analysis
  60. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  61. GRB050117b: Swift-BAT detection of a weak burst
  62. GRB050117: optical observation
  63. GRB 050117, I-band observations
  64. GRB 050117: Optical observation
  65. GRB050117: Refined XRT position
  66. GRB050117: MASTER optical observations
  67. MASTER:GRB050117 SWIFT
  68. GRB050117: Swift-BAT detection of a long multi-peaked burst
  69. GRB050117: Swift XRT Position
  70. SGR1806-20: Swift-BAT observations of two additional bursts
  71. SGR 1806-20, RHESSI observations of the 041227 giant flare
  72. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  73. GRB 041217: Optical observations
  74. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  75. GRB041228: ROTSE-III Optical Observations
  76. GRB041228: Swift-BAT detection of a burst
  77. GRB041219; RXTE ASM Observations
  78. NIR Observations of GRB 041219
  79. GRB041226: ROTSE-III Optical Observations
  80. GRB041226: Swift-BAT detection of a burst
  81. GRB041223: decay of the afterglow
  82. GRB041224: ROTSE-III Optical Observations
  83. GRB 041223: XRT afterglow spectrum and light curve
  84. GRB 041223 Fluence measured by Swift-BAT
  85. GRB041224: Swift-BAT detection of a soft burst
  86. GRB041223: optical and NIR observations with REM
  87. Swift-BAT Time History of GRB041219
  88. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  89. GRB041223: ROTSE-III Optical Observations
  90. GRB041223: Swift-BAT detection of a bright long burst
  91. GRB041220: Swift-BAT burst
  92. GRB 041219 Optical Observations
  93. GRB041219c: Third Burst in One Day from Swift-BAT
  94. GRB041219b: A Swift-BAT burst
  95. Swift-BAT detection of the bright long burst GRB041219
  96. GRB041217: optical limit 30 min after GRB
  97. GRB041217: Optical Observations
  98. GRB041217: NIR and optical observations with REM
  99. GRB041217: P60 Optical Observations
  100. GRB041217: Infrared Observations

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