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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19590 results found.

  1. Swift Detection of GRB050509b: A short duration burst
  2. GRB 050509a: Swift XRT Position
  3. Swift Detection of the Burst GRB050509
  4. Swift-BAT detection of GRB 050507
  5. GRB 050505: early time observations
  6. GRB 050505 - Faulkes Telescope North observations
  7. GRB 050502a: Swift XRT Upper Limit
  8. GRB 050505, simultaneous optical observation
  9. GRB 050505: Further Swift UVOT observations.
  10. GRB050416A : 1 GHz limit from GMRT
  11. GRB 050505 UVOT
  12. GRB 050505: Swift XRT Position
  13. GRB050505 Swift-BAT refined analysis
  14. GRB 050416b:Swift XRT afterglow upper limits
  15. GRB 050416b:Swift XRT afterglow upper limits
  16. Swift-BAT detection of GRB050505
  17. GRB 050504: Swift XRT position
  18. Swift UVOT observation of GRB 050504
  19. GRB 050502b, V band Observations
  20. GRB050502B Swift-BAT refined analysis
  21. GRB050502B: I band source in XRT error circle
  22. Swift UVOT refined analysis
  23. Retraction of Swift-BAT trigger 116145
  24. GRB 050502b : optical observation at Lulin observatory
  25. GRB 050502b: Swift XRT Position
  26. GRB050502B: Optical Limits from ANU 1m
  27. Swift Detection of the Bright Burst GRB050502b
  28. GRB050502: ANU 1m optical Observations
  29. Swift-BAT Trigger 115881 is not a real GRB
  30. Swift/BAT possible detection of a weak burst GRB050430
  31. GRB 050401: Rc observation
  32. GRB050416a: Radio Detection
  33. GRB 050422: Swift-UVOT observation
  34. GRB 050422: Swift-BAT refined analysis
  35. GRB 050422: Swift XRT Position
  36. Swift Detection of GRB 050422
  37. GRB 050421: SLOTIS observations
  38. GRB050421: Radio Observations
  39. GRB050421: Radio Observations
  40. GRB 050421: Swift-UVOT observation
  41. GRB 050421: Swift-BAT refined analysis
  42. GRB 050421: ROTSE-III Optical Limits
  43. GRB 050421: early Swift XRT analysis results
  44. GRB 050421: BOOTES-2 simultaneous optical observations
  45. GRB 050421: Optical observations at the INT
  46. Swift Detection of GRB050421
  47. GRB 050416b: Tentative Swift XRT Position
  48. GRB050326: analysis of the XMM-Newton observation
  49. GRB 050418: Swift-BAT refined analysis
  50. Swift-BAT detection of the bright and long GRB 050418
  51. GRB 050416B: optical observations
  52. GRB 050416b: Swift-BAT refined analysis
  53. GRB 050416: Swift/UVOT refined analysis
  54. Swift-BAT detection of GRB 050416b
  55. GRB050412: Radio Observations
  56. GRB 050416: Swift/UVOT detection of afterglow emission
  57. GRB050416: Refined Swift-XRT analysis
  58. GRB050416: Maidanak optical observations
  59. GRB 050416: Swift-BAT refined analysis
  60. GRB 050416,optical observation
  61. GRB 050416: KAIT observations
  62. GRB 050416: Swift XRT Position
  63. GRB 050416: Radio observations
  64. Confirmation of OT for GRB050416
  65. GRB050416: P60 Afterglow Candidate
  66. Swift BAT/XRT Detection of GRB 050416
  67. GRB 050412: Subaru observations
  68. GRB 050412: optical limit
  69. GRB 050412: optical observations
  70. GRB 050408: refined XRT analysis, no jet break seen yet
  71. GRB 050412: early Swift XRT analysis results
  72. GRB 050412: Swift-BAT refined analysis
  73. GRB 050412: ANU 2.3m observations
  74. GRB 050412: Early Optical/Ultraviolet Observations with
  75. GRB 050412: retraction of UVOT transient report
  76. GRB 050412: UVOT transient not in XRT error circle
  77. GRB 050412: Swift XRT Position
  78. GRB050412: optical limit before and during GRB
  79. GRB050412: ROTSE-III Optical Limits
  80. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  81. GRB 050412: IR Observations
  82. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  83. GRB 050410, optical observations
  84. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  85. GRB 050410 R band Optical Observations
  86. GRB050410 : Null detection report
  87. GRB 050410, optical observations
  88. GRB050410: Radio Observations
  89. GRB 050408: Swift XRT measurement of possible jet break
  90. GRB050410: MASTER optical observations
  91. GRB 050410: Early observations with Swift-UVOT
  92. Swift-BAT detection of GRB 050410
  93. GRB 050410: Swift XRT Position
  94. GRB 050408: Properties of the Host Galaxy
  95. GRB 050408: Swift XRT analysis
  96. GRB 050408, optical observations
  97. GRB050408: REM NIR and Optical observation
  98. GRB 050408 Optical Observations
  99. GRB 050408: Optical afterglow confirmed
  100. GRB 050408, optical observations

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