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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"

24167 results found.

  1. Swift Detection of the Burst GRB050509
  2. Swift-BAT detection of GRB 050507
  3. GRB 050505: early time observations
  4. GRB 050505 - Faulkes Telescope North observations
  5. GRB 050505, simultaneous optical observation
  6. GRB050505: Infrared observations
  7. GRB 050505: Further Swift UVOT observations.
  8. GRB 050505 UVOT
  9. GRB 050505: Swift XRT Position
  10. GRB050505 Swift-BAT refined analysis
  11. GRB 050416b:Swift XRT afterglow upper limits
  12. GRB 050416b:Swift XRT afterglow upper limits
  13. Swift-BAT detection of GRB050505
  14. Swift UVOT observation of GRB 050504
  15. GRB050504: Faulkes North optical robotic limit
  16. GRB 050502b, V band Observations
  17. GRB (?) 050504: IR Observations, Intriguing Source
  18. Renewal of SGR 1806-20 activity
  19. GRB050502B Swift-BAT refined analysis
  20. Swift UVOT refined analysis
  21. Retraction of Swift-BAT trigger 116145
  22. GRB 050502b: Swift XRT Position
  23. Swift Detection of the Bright Burst GRB050502b
  24. GRB050502: ANU 1m optical Observations
  25. GRB 050502: ROTSE-III Detection of Possible Counterpart
  26. Swift-BAT Trigger 115881 is not a real GRB
  27. Swift/BAT possible detection of a weak burst GRB050430
  28. GRB 050422: Swift-UVOT observation
  29. GRB 050422: Swift-BAT refined analysis
  30. GRB 050422: Swift XRT Position
  31. Swift Detection of GRB 050422
  32. GRB 050421: SLOTIS observations
  33. GRB050421: Radio Observations
  34. GRB050421: Radio Observations
  35. GRB 050421: Swift-UVOT observation
  36. GRB 050421: Swift-BAT refined analysis
  37. GRB 050421: ROTSE-III Optical Limits
  38. GRB050421
  39. GRB 050421: early Swift XRT analysis results
  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 050418: Swift-BAT refined analysis
  45. Swift-BAT detection of the bright and long GRB 050418
  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. GRB 050416: Swift/UVOT detection of afterglow emission
  54. GRB050416: Refined Swift-XRT analysis
  55. GRB 050416: Swift-BAT refined analysis
  56. GRB 050416: ART observations
  57. GRB 050416,optical observation
  58. GRB 050416: KAIT observations
  59. GRB 050416: Swift XRT Position
  60. GRB 050416: Radio observations
  61. Confirmation of OT for GRB050416
  62. Swift BAT/XRT Detection of GRB 050416
  63. GRB 050412: PROMPT VRcIc Observations
  64. GRB 050412: optical limit
  65. GRB 050412: early Swift XRT analysis results
  66. GRB 050412: Swift-BAT refined analysis
  67. GRB 050412: Optical limit
  68. GRB 050412: Optical observations
  69. GRB 050412: Swift XRT Position
  70. GRB050412: optical limit before and during GRB
  71. GRB 050412: LCO optical observations
  72. GRB050412: ROTSE-III Optical Limits
  73. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  74. GRB 050412: IR Observations
  75. GRB 050401: Optical limit
  76. GRB 050408: Optical limit
  77. GRB 050410, optical observations
  78. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  79. GRB 050410 R band Optical Observations
  80. GRB 050408: Swift XRT measurement of possible jet break
  81. GRB 050410: Early observations with Swift-UVOT
  82. Swift-BAT detection of GRB 050410
  83. GRB 050410: Swift XRT Position
  84. GRB 050408: Swift XRT analysis
  85. GRB 050408,optical observation
  86. GRB 050408: Magellan astrometry and photometry
  87. GRB 050408: ROTSE-III Optical Limits
  88. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  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 Optical Observations
  98. GRB 050401 BAT refined analysis
  99. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  100. GRB 050402: Early observations with Swift-UVOT

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