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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').

18175 results found.

  1. Swift-BAT detection of GRB050505
  2. GRB 050504: Swift XRT position
  3. Swift UVOT observation of GRB 050504
  4. GRB 050502b, V band Observations
  5. GRB050502B Swift-BAT refined analysis
  6. GRB050502B: I band source in XRT error circle
  7. Swift UVOT refined analysis
  8. Retraction of Swift-BAT trigger 116145
  9. GRB 050502b : optical observation at Lulin observatory
  10. GRB 050502b: Swift XRT Position
  11. GRB050502B: Optical Limits from ANU 1m
  12. Swift Detection of the Bright Burst GRB050502b
  13. GRB050502: ANU 1m optical Observations
  14. Swift-BAT Trigger 115881 is not a real GRB
  15. Swift/BAT possible detection of a weak burst GRB050430
  16. GRB 050401: Rc observation
  17. GRB050416a: Radio Detection
  18. GRB 050422: Swift-UVOT observation
  19. GRB 050422: Swift-BAT refined analysis
  20. GRB 050422: Swift XRT Position
  21. Swift Detection of GRB 050422
  22. GRB 050421: SLOTIS observations
  23. GRB050421: Radio Observations
  24. GRB050421: Radio Observations
  25. GRB 050421: Swift-UVOT observation
  26. GRB 050421: Swift-BAT refined analysis
  27. GRB 050421: ROTSE-III Optical Limits
  28. GRB 050421: early Swift XRT analysis results
  29. GRB 050421: BOOTES-2 simultaneous optical observations
  30. GRB 050421: Optical observations at the INT
  31. Swift Detection of GRB050421
  32. GRB 050416b: Tentative Swift XRT Position
  33. GRB050326: analysis of the XMM-Newton observation
  34. GRB 050418: Swift-BAT refined analysis
  35. Swift-BAT detection of the bright and long GRB 050418
  36. GRB 050416B: optical observations
  37. GRB 050416b: Swift-BAT refined analysis
  38. GRB 050416: Swift/UVOT refined analysis
  39. Swift-BAT detection of GRB 050416b
  40. GRB050412: Radio Observations
  41. GRB 050416: Swift/UVOT detection of afterglow emission
  42. GRB050416: Refined Swift-XRT analysis
  43. GRB050416: Maidanak optical observations
  44. GRB 050416: Swift-BAT refined analysis
  45. GRB 050416,optical observation
  46. GRB 050416: KAIT observations
  47. GRB 050416: Swift XRT Position
  48. GRB 050416: Radio observations
  49. Confirmation of OT for GRB050416
  50. GRB050416: P60 Afterglow Candidate
  51. Swift BAT/XRT Detection of GRB 050416
  52. GRB 050412: Subaru observations
  53. GRB 050412: optical limit
  54. GRB 050412: optical observations
  55. GRB 050408: refined XRT analysis, no jet break seen yet
  56. GRB 050412: early Swift XRT analysis results
  57. GRB 050412: Swift-BAT refined analysis
  58. GRB 050412: ANU 2.3m observations
  59. GRB 050412: Early Optical/Ultraviolet Observations with
  60. GRB 050412: retraction of UVOT transient report
  61. GRB 050412: UVOT transient not in XRT error circle
  62. GRB 050412: Swift XRT Position
  63. GRB050412: optical limit before and during GRB
  64. GRB050412: ROTSE-III Optical Limits
  65. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  66. GRB 050412: IR Observations
  67. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  68. GRB 050410, optical observations
  69. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  70. GRB 050410 R band Optical Observations
  71. GRB050410 : Null detection report
  72. GRB 050410, optical observations
  73. GRB050410: Radio Observations
  74. GRB 050408: Swift XRT measurement of possible jet break
  75. GRB050410: MASTER optical observations
  76. GRB 050410: Early observations with Swift-UVOT
  77. Swift-BAT detection of GRB 050410
  78. GRB 050410: Swift XRT Position
  79. GRB 050408: Properties of the Host Galaxy
  80. GRB 050408: Swift XRT analysis
  81. GRB 050408, optical observations
  82. GRB050408: REM NIR and Optical observation
  83. GRB 050408 Optical Observations
  84. GRB 050408: Optical afterglow confirmed
  85. GRB 050408, optical observations
  86. GRB 050408 optical candidate
  87. GRB 050408: Swift XRT Position
  88. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  89. GRB 050406: early Swift XRT analysis results
  90. GRB 050406 BAT refined analysis
  91. GRB 050406: Early observations with Swift-UVOT
  92. GRB 050406: Swift XRT Position
  93. Swift-BAT detection of GRB 050406
  94. Konus-Wind observation of GRB 050401
  95. GRB050401: Radio observation at 610 MHz with GMRT
  96. GRB 050401: VLT spectroscopic redshift
  97. GRB 050401 Optical Observations
  98. GRB050401: Maidanak optical observation
  99. GRB 050401 BAT refined analysis
  100. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)

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