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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"

35273 results found.

  1. Swift UVOT refined analysis
  2. Retraction of Swift-BAT trigger 116145
  3. GRB 050502a : R band observation at Lulin observatory
  4. GRB 050502b : optical observation at Lulin observatory
  5. GRB 050502b: Swift XRT Position
  6. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  7. GRB 050502: INTEGRAL results
  8. GRB050502: ANU 1m optical Observations
  9. GRB 050502: Confirmed variability of the afterglow candidate +
  10. GRB 050502: PAIRITEL IR Observations
  11. GRB050502 - Correction on the Optical Candidate from the Liverpool
  12. GRB 050502 - A long GRB detected with INTEGRAL
  13. GRB 050502: ROTSE-III Detection of Possible Counterpart
  14. Swift-BAT Trigger 115881 is not a real GRB
  15. Swift/BAT possible detection of a weak burst GRB050430
  16. GRB 050401: Rc observation
  17. GRB050416a: Radio Detection
  18. GRB 050422: Swift-UVOT observation
  19. GRB 050422: Swift-BAT refined analysis
  20. GRB 050422: Swift XRT Position
  21. Swift Detection of GRB 050422
  22. GRB 050421: NIR observations
  23. GRB 050416: Optical/NIR observations
  24. GRB 050421: SLOTIS observations
  25. GRB 050421: Further Analysis of IR imaging
  26. GRB050421: Radio Observations
  27. GRB050421: Radio Observations
  28. GRB 050421: Swift-UVOT observation
  29. GRB 050421: IR Observations
  30. GRB 050421: Swift-BAT refined analysis
  31. GRB 050421: ROTSE-III Optical Limits
  32. GRB 050421: NIR observations re-examination
  33. GRB 050421: early Swift XRT analysis results
  34. GRB 050421: NIR observations
  35. GRB050421: P60 Observations
  36. GRB 050421: BOOTES-2 simultaneous optical observations
  37. GRB 050421: Optical observations at the INT
  38. GRB 050416b: Tentative Swift XRT Position
  39. GRB 050315: potential host galaxy
  40. GRB 050412: Chandra observations
  41. GRB050416A, optical observations
  42. GRB 050418: Swift-BAT refined analysis
  43. Swift-BAT detection of the bright and long GRB 050418
  44. GRB 050416: Mitsume optical observation
  45. GRB 050416 : optical observation at Xinglong observatory
  46. GRB 050416B: optical observations
  47. GRB 050416b: Swift-BAT refined analysis
  48. GRB 050416b: LCO observations
  49. GRB 050416b: LCO observations
  50. GRB050416B: IR observations
  51. GRB 050416: Swift/UVOT refined analysis
  52. Swift-BAT detection of GRB 050416b
  53. IBAS GRB Alert # 2463: not a GRB
  54. GRB050412: Radio Observations
  55. GRB 050416: Swift/UVOT detection of afterglow emission
  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. GRB 050408: RTT150 optical observations
  68. GRB 050412: PROMPT VRcIc Observations
  69. GRB 050408: Kuiper 1.5m 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 : XingLong optical observation
  75. GRB 050412: Swift-BAT refined analysis
  76. GRB 050412: ANU 2.3m observations
  77. GRB 050412: Early Optical/Ultraviolet Observations with
  78. GRB 050412: retraction of UVOT transient report
  79. GRB 050412: UVOT transient not in XRT error circle
  80. GRB 050408: SDSS Field Calibration
  81. GRB 050412: Optical limit
  82. GRB 050412: LCO Optical Observations
  83. GRB 050412: Optical observations
  84. GRB050412: P60 Observations
  85. GRB 050412: Swift XRT Position
  86. GRB050412: optical limit before and during GRB
  87. GRB 050412: LCO optical observations
  88. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  89. GRB 050412: IR and Optical observations
  90. GRB 050412: IR Observations
  91. GRB050408: Radio Observations
  92. GRB 050401: Optical limit
  93. GRB 050408: Optical limit
  94. GRB050410: P60 Observations
  95. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  96. GRB 050410, optical observations
  97. GRB 050408: PROMPT VRcIc Observations
  98. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  99. GRB 050410 R band Optical Observations
  100. GRB050410 : Null detection report

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