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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"

32489 results found.

  1. GRB050502a: P60 Observations
  2. GRB 050502a: RBO Observations
  3. GRB 050502A: WSRT Radio Observations
  4. GRB050502A: Optical Observations
  5. GRB050502B Swift-BAT refined analysis
  6. GRB050502B: I band source in XRT error circle
  7. Swift UVOT refined analysis
  8. Retraction of Swift-BAT trigger 116145
  9. GRB 050502a : R band observation at Lulin observatory
  10. GRB 050502b : optical observation at Lulin observatory
  11. GRB 050502b: Swift XRT Position
  12. GRB050502B: Optical Limits from ANU 1m
  13. GRB 050502: INTEGRAL results
  14. GRB050502: ANU 1m optical Observations
  15. GRB 050502: Confirmed variability of the afterglow candidate +
  16. GRB 050502: PAIRITEL IR Observations
  17. GRB 050502: ROTSE-III Detection of Possible Counterpart
  18. Swift-BAT Trigger 115881 is not a real GRB
  19. Swift/BAT possible detection of a weak burst GRB050430
  20. GRB 050401: Rc observation
  21. GRB050416a: Radio Detection
  22. GRB 050422: Swift-UVOT observation
  23. GRB 050422: Swift-BAT refined analysis
  24. GRB 050422: Swift XRT Position
  25. GRB 050421: NIR observations
  26. GRB 050416: Optical/NIR observations
  27. GRB 050421: SLOTIS observations
  28. GRB 050421: Further Analysis of IR imaging
  29. GRB050421: Radio Observations
  30. GRB050421: Radio Observations
  31. GRB 050421: Swift-UVOT observation
  32. GRB 050421: IR Observations
  33. GRB 050421: Swift-BAT refined analysis
  34. GRB 050421: ROTSE-III Optical Limits
  35. GRB 050421: NIR observations re-examination
  36. GRB050421
  37. GRB 050421: early Swift XRT analysis results
  38. GRB 050421: NIR observations
  39. GRB050421: P60 Observations
  40. GRB 050421: BOOTES-2 simultaneous optical observations
  41. GRB 050421: Optical observations at the INT
  42. Swift Detection of GRB050421
  43. GRB 050416b: Tentative Swift XRT Position
  44. GRB 050315: potential host galaxy
  45. GRB050418: Null Optical Observations
  46. GRB 050412: Chandra observations
  47. GRB050416A, optical observations
  48. GRB 050418: Swift-BAT refined analysis
  49. GRB 050416: Mitsume optical observation
  50. GRB 050416 : optical observation at Xinglong observatory
  51. GRB 050416B: optical observations
  52. GRB 050416b: Swift-BAT refined analysis
  53. GRB 050416b: LCO observations
  54. GRB 050416b: LCO observations
  55. GRB050416B: IR observations
  56. GRB 050416: Swift/UVOT refined analysis
  57. GRB050412: Radio Observations
  58. GRB 050416: Swift/UVOT detection of afterglow emission
  59. GRB050416: Refined Swift-XRT analysis
  60. GRB 050416: Swift-BAT refined analysis
  61. GRB 050416: ART observations
  62. GRB 050416: KAIT observations
  63. GRB050416: P200 NIR Observations
  64. GRB 050416: Swift XRT Position
  65. GRB 050416: Radio observations
  66. GRB 050412: Subaru observations
  67. GRB 050408: RTT150 optical observations
  68. GRB050408: optical observation
  69. GRB 050412: PROMPT VRcIc Observations
  70. GRB 050408: Kuiper 1.5m observations
  71. GRB 050412: optical limit
  72. GRB 050412: optical observations
  73. GRB 050408: refined XRT analysis, no jet break seen yet
  74. GRB 050412: early Swift XRT analysis results
  75. GRB 050412 : XingLong optical observation
  76. GRB 050412: Swift-BAT refined analysis
  77. GRB 050412: ANU 2.3m observations
  78. GRB 050412: Early Optical/Ultraviolet Observations with
  79. GRB 050412: retraction of UVOT transient report
  80. GRB 050412: Optical limit
  81. GRB 050412: LCO Optical Observations
  82. GRB 050412: Optical observations
  83. GRB050412: P60 Observations
  84. GRB 050412: Swift XRT Position
  85. GRB050412: optical limit before and during GRB
  86. GRB 050412: LCO optical observations
  87. GRB050412: ROTSE-III Optical Limits
  88. GRB050408: Radio Observations
  89. GRB 050401: Optical limit
  90. GRB 050408: Optical limit
  91. GRB050410: P60 Observations
  92. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  93. GRB 050410, optical observations
  94. GRB 050408: PROMPT VRcIc Observations
  95. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  96. GRB050410 : Null detection report
  97. GRB 050410, optical observations
  98. GRB050410: Radio Observations
  99. GRB 050410: Early observations with Swift-UVOT
  100. Swift-BAT detection of GRB 050410

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