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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').

18008 results found.

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

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