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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"

26033 results found.

  1. GRB 050502A: WSRT Radio Observations
  2. GRB050502A: Optical Observations
  3. GRB050502B Swift-BAT refined analysis
  4. GRB050502B: I band source in XRT error circle
  5. Swift UVOT refined analysis
  6. Retraction of Swift-BAT trigger 116145
  7. GRB 050502a : R band observation at Lulin observatory
  8. GRB 050502b : optical observation at Lulin observatory
  9. GRB 050502b: Swift XRT Position
  10. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  11. GRB050502B: Optical Limits from ANU 1m
  12. Swift Detection of the Bright Burst GRB050502b
  13. GRB050502: ANU 1m optical Observations
  14. GRB 050502: Confirmed variability of the afterglow candidate +
  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: NIR observations
  24. GRB 050416: Optical/NIR observations
  25. GRB 050421: SLOTIS observations
  26. GRB 050421: Further Analysis of IR imaging
  27. GRB050421: Radio Observations
  28. GRB050421: Radio Observations
  29. GRB 050421: Swift-UVOT observation
  30. GRB 050421: IR Observations
  31. GRB 050421: Swift-BAT refined analysis
  32. GRB 050421: ROTSE-III Optical Limits
  33. GRB 050421: NIR observations re-examination
  34. GRB 050421: early Swift XRT analysis results
  35. GRB 050421: NIR observations
  36. GRB050421: P60 Observations
  37. GRB 050421: BOOTES-2 simultaneous optical observations
  38. GRB 050421: Optical observations at the INT
  39. Swift Detection of GRB050421
  40. GRB 050416b: Tentative Swift XRT Position
  41. GRB 050315: potential host galaxy
  42. GRB050326: analysis of the XMM-Newton observation
  43. GRB 050412: Chandra observations
  44. GRB 050418: Swift-BAT refined analysis
  45. Swift-BAT detection of the bright and long GRB 050418
  46. GRB 050416: Mitsume optical observation
  47. GRB 050416 : optical observation at Xinglong observatory
  48. GRB 050416B: optical observations
  49. GRB 050416b: Swift-BAT refined analysis
  50. GRB 050416: Swift/UVOT refined analysis
  51. Swift-BAT detection of GRB 050416b
  52. GRB050412: Radio Observations
  53. GRB 050416: Swift/UVOT detection of afterglow emission
  54. GRB050416: Refined Swift-XRT analysis
  55. GRB050416: Maidanak optical observations
  56. GRB 050416: Swift-BAT refined analysis
  57. GRB 050416: ART observations
  58. GRB 050416,optical observation
  59. GRB 050416: KAIT observations
  60. GRB050416: P200 NIR Observations
  61. GRB 050416: Swift XRT Position
  62. GRB 050416: Radio observations
  63. Confirmation of OT for GRB050416
  64. GRB050416: P60 Afterglow Candidate
  65. Swift BAT/XRT Detection of GRB 050416
  66. GRB 050412: Subaru observations
  67. GRB050408: optical observation
  68. GRB 050412: PROMPT VRcIc Observations
  69. GRB 050412: optical limit
  70. GRB 050412: optical observations
  71. GRB 050408: refined XRT analysis, no jet break seen yet
  72. GRB 050412: early Swift XRT analysis results
  73. GRB 050412 : XingLong optical observation
  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: LCO Optical Observations
  80. GRB 050412: Optical observations
  81. GRB050412: P60 Observations
  82. GRB 050412: Swift XRT Position
  83. GRB050412: optical limit before and during GRB
  84. GRB050412: ROTSE-III Optical Limits
  85. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  86. GRB 050412: IR Observations
  87. GRB050408: Radio Observations
  88. GRB 050401: Optical limit
  89. GRB 050408: Optical limit
  90. GRB050410: P60 Observations
  91. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  92. GRB 050410, optical observations
  93. GRB 050408: PROMPT VRcIc Observations
  94. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  95. GRB 050410 R band Optical Observations
  96. GRB050410 : Null detection report
  97. GRB 050410, optical observations
  98. GRB050410: Radio Observations
  99. GRB 050408: Swift XRT measurement of possible jet break
  100. GRB050410: MASTER optical observations

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