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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"

19596 results found.

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

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