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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').

17103 results found.

  1. GRB 050223 Swift/BAT detection of a burst
  2. GRB 050223: Swift XRT Position
  3. GRB050219b: CORRECTION to time of UVOT observations
  4. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  5. GRB 050219b: CORRECTION to refined XRT position
  6. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  7. GRB 050219b: Refined XRT position
  8. GRB 050219b: Swift-BAT detection of a burst
  9. GRB 050219b: CORRECTION: Swift XRT Position
  10. GRB 050219b: Swift XRT Position
  11. GRB 050219a, optical observations
  12. GRB 050219a: Refined XRT position
  13. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  14. GRB 050219: Swift-BAT detection of a burst
  15. GRB050215b: Swift UVOT Detection of Afterglow Emission
  16. GRB 050219: Prompt X-ray position
  17. GRB 050215b: XRT confirmation of IR afterglow candidate
  18. GRB050215b: P60 Optical Observations
  19. GRB 050215b: Swift XRT Source Variability
  20. GRB 050215B: candidate afterglow
  21. GRB 050215b : Lulin follow-up observation
  22. GRB 050215b, BOOTES-2 simultaneous optical observations
  23. GRB 050215B: UKIRT K-band imaging
  24. GRB 050215b: Swift XRT Observations
  25. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  26. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  27. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  28. GRB050215B: ROTSE-III optical observations
  29. GRB050215A: ROTSE-III Optical Observations
  30. short/hard GRB 050202, optical observations
  31. GRB 050128: Radio observations
  32. Further analysis of the short Swift-BAT GRB 050202
  33. GRB 050202: Second epoch radio observations
  34. GRB050202: Radio Observations
  35. GRB 050202: Short burst detected by Swift-BAT
  36. SGR1806-20: Swift-BAT detection of a large normal burst
  37. GRB050128: Faulkes Telescope South observations
  38. GRB050128,optical observations
  39. GRB050126: Updated Swift XRT Position
  40. GRB 050126: Radio Observations
  41. GRB050128 Swift-BAT observations
  42. GRB 050128: Swift XRT prompt afterglow position
  43. GRB 050124: K-band afterglow observations
  44. GRB050126: MASTER optical limit for KECK OT
  45. GRB050126: Burst Parameters Measured by BAT
  46. GRB050126: MASTER optical observations
  47. GRB 050126: Prompt XRT detection and localization
  48. GRB050124: No Swift UVOT Detection of Afterglow Emission
  49. GRB 050117a: Radio Observations
  50. GRB050124,optical observation
  51. GRB050124: Updated Swift XRT Position and Fluxes
  52. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  53. GRB050124: Refined BAT position, spectral and fluence information
  54. GRB050124: Swift-BAT position of a double-peaked burst
  55. GRB050117a: Radio Observations
  56. GRB050117a: Refined analysis
  57. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  58. GRB050117b: Swift-BAT detection of a weak burst
  59. GRB050117: optical observation
  60. GRB 050117, I-band observations
  61. GRB 050117: Optical observation
  62. GRB050117: Refined XRT position
  63. GRB050117: MASTER optical observations
  64. MASTER:GRB050117 SWIFT
  65. GRB050117: Swift-BAT detection of a long multi-peaked burst
  66. GRB050117: Swift XRT Position
  67. SGR1806-20: Swift-BAT observations of two additional bursts
  68. SGR 1806-20, RHESSI observations of the 041227 giant flare
  69. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  70. GRB 041217: Optical observations
  71. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  72. GRB041228: ROTSE-III Optical Observations
  73. GRB041228: Swift-BAT detection of a burst
  74. GRB041219; RXTE ASM Observations
  75. NIR Observations of GRB 041219
  76. GRB041226: ROTSE-III Optical Observations
  77. GRB041226: Swift-BAT detection of a burst
  78. GRB041223: decay of the afterglow
  79. GRB041224: ROTSE-III Optical Observations
  80. GRB 041223: XRT afterglow spectrum and light curve
  81. GRB 041223 Fluence measured by Swift-BAT
  82. GRB041224: Swift-BAT detection of a soft burst
  83. GRB041223: optical and NIR observations with REM
  84. Swift-BAT Time History of GRB041219
  85. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  86. GRB041223: ROTSE-III Optical Observations
  87. GRB041223: Swift-BAT detection of a bright long burst
  88. GRB041220: Swift-BAT burst
  89. GRB 041219 Optical Observations
  90. GRB041219c: Third Burst in One Day from Swift-BAT
  91. GRB041219b: A Swift-BAT burst
  92. Swift-BAT detection of the bright long burst GRB041219
  93. GRB041217: optical limit 30 min after GRB
  94. GRB041217: Optical Observations
  95. GRB041217: NIR and optical observations with REM
  96. GRB041217: P60 Optical Observations
  97. GRB041217: Infrared Observations
  98. GRB041217: The First GRB Located On-Board Swift
  99. GRB040916: Optical observations
  100. GRB040422: optical and NIR observations at the VLT

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