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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"

19192 results found.

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

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