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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"

19168 results found.

  1. Retraction of Swift-BAT trigger 116145
  2. GRB 050502b : optical observation at Lulin observatory
  3. GRB 050502b: Swift XRT Position
  4. GRB050502B: Optical Limits from ANU 1m
  5. Swift Detection of the Bright Burst GRB050502b
  6. GRB050502: ANU 1m optical Observations
  7. Swift-BAT Trigger 115881 is not a real GRB
  8. Swift/BAT possible detection of a weak burst GRB050430
  9. GRB 050401: Rc observation
  10. GRB050416a: Radio Detection
  11. GRB 050422: Swift-UVOT observation
  12. GRB 050422: Swift-BAT refined analysis
  13. GRB 050422: Swift XRT Position
  14. Swift Detection of GRB 050422
  15. GRB 050421: SLOTIS observations
  16. GRB050421: Radio Observations
  17. GRB050421: Radio Observations
  18. GRB 050421: Swift-UVOT observation
  19. GRB 050421: Swift-BAT refined analysis
  20. GRB 050421: ROTSE-III Optical Limits
  21. GRB 050421: early Swift XRT analysis results
  22. GRB 050421: BOOTES-2 simultaneous optical observations
  23. GRB 050421: Optical observations at the INT
  24. Swift Detection of GRB050421
  25. GRB 050416b: Tentative Swift XRT Position
  26. GRB050326: analysis of the XMM-Newton observation
  27. GRB 050418: Swift-BAT refined analysis
  28. Swift-BAT detection of the bright and long GRB 050418
  29. GRB 050416B: optical observations
  30. GRB 050416b: Swift-BAT refined analysis
  31. GRB 050416: Swift/UVOT refined analysis
  32. Swift-BAT detection of GRB 050416b
  33. GRB050412: Radio Observations
  34. GRB 050416: Swift/UVOT detection of afterglow emission
  35. GRB050416: Refined Swift-XRT analysis
  36. GRB050416: Maidanak optical observations
  37. GRB 050416: Swift-BAT refined analysis
  38. GRB 050416,optical observation
  39. GRB 050416: KAIT observations
  40. GRB 050416: Swift XRT Position
  41. GRB 050416: Radio observations
  42. Confirmation of OT for GRB050416
  43. GRB050416: P60 Afterglow Candidate
  44. Swift BAT/XRT Detection of GRB 050416
  45. GRB 050412: Subaru observations
  46. GRB 050412: optical limit
  47. GRB 050412: optical observations
  48. GRB 050408: refined XRT analysis, no jet break seen yet
  49. GRB 050412: early Swift XRT analysis results
  50. GRB 050412: Swift-BAT refined analysis
  51. GRB 050412: ANU 2.3m observations
  52. GRB 050412: Early Optical/Ultraviolet Observations with
  53. GRB 050412: retraction of UVOT transient report
  54. GRB 050412: UVOT transient not in XRT error circle
  55. GRB 050412: Swift XRT Position
  56. GRB050412: optical limit before and during GRB
  57. GRB050412: ROTSE-III Optical Limits
  58. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  59. GRB 050412: IR Observations
  60. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  61. GRB 050410, optical observations
  62. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  63. GRB 050410 R band Optical Observations
  64. GRB050410 : Null detection report
  65. GRB 050410, optical observations
  66. GRB050410: Radio Observations
  67. GRB 050408: Swift XRT measurement of possible jet break
  68. GRB050410: MASTER optical observations
  69. GRB 050410: Early observations with Swift-UVOT
  70. Swift-BAT detection of GRB 050410
  71. GRB 050410: Swift XRT Position
  72. GRB 050408: Properties of the Host Galaxy
  73. GRB 050408: Swift XRT analysis
  74. GRB 050408, optical observations
  75. GRB050408: REM NIR and Optical observation
  76. GRB 050408 Optical Observations
  77. GRB 050408: Optical afterglow confirmed
  78. GRB 050408, optical observations
  79. GRB 050408 optical candidate
  80. GRB 050408: Swift XRT Position
  81. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  82. GRB 050406: early Swift XRT analysis results
  83. GRB 050406 BAT refined analysis
  84. GRB 050406: Early observations with Swift-UVOT
  85. GRB 050406: Swift XRT Position
  86. Swift-BAT detection of GRB 050406
  87. Konus-Wind observation of GRB 050401
  88. GRB050401: Radio observation at 610 MHz with GMRT
  89. GRB 050401: VLT spectroscopic redshift
  90. GRB 050401 Optical Observations
  91. GRB050401: Maidanak optical observation
  92. GRB 050401 BAT refined analysis
  93. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  94. GRB 050402A: IR Observations
  95. GRB 050402: Early observations with Swift-UVOT
  96. Swift Trigger 113225: P60 Observations
  97. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  98. GRB 050401: Optical afterglow candidate
  99. Swift-BAT detection of GRB 050401
  100. GRB 050401: Prompt XRT position

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