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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"

18476 results found.

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

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