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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"

27039 results found.

  1. Swift Detection of GRB050509b: A short duration burst
  2. Swift Detection of the Burst GRB050509
  3. Swift-BAT detection of GRB 050507
  4. GRB050505: Infrared observations
  5. GRB 050505: Further Swift UVOT observations.
  6. GRB 050505 UVOT
  7. GRB050505 Swift-BAT refined analysis
  8. GRB 050416b:Swift XRT afterglow upper limits
  9. GRB 050416b:Swift XRT afterglow upper limits
  10. Swift-BAT detection of GRB050505
  11. Swift UVOT observation of GRB 050504
  12. GRB050504: Faulkes North optical robotic limit
  13. GRB 050502b, V band Observations
  14. GRB (?) 050504: IR Observations, Intriguing Source
  15. Renewal of SGR 1806-20 activity
  16. GRB050502B Swift-BAT refined analysis
  17. Swift UVOT refined analysis
  18. Retraction of Swift-BAT trigger 116145
  19. Swift Detection of the Bright Burst GRB050502b
  20. GRB 050502: ROTSE-III Detection of Possible Counterpart
  21. Swift-BAT Trigger 115881 is not a real GRB
  22. Swift/BAT possible detection of a weak burst GRB050430
  23. GRB 050422: Swift-UVOT observation
  24. GRB 050422: Swift-BAT refined analysis
  25. Swift Detection of GRB 050422
  26. GRB 050421: SLOTIS observations
  27. GRB 050421: Swift-UVOT observation
  28. GRB 050421: Swift-BAT refined analysis
  29. GRB 050421: ROTSE-III Optical Limits
  30. GRB050421
  31. GRB 050421: early Swift XRT analysis results
  32. Swift Detection of GRB050421
  33. GRB 050418: Swift-BAT refined analysis
  34. Swift-BAT detection of the bright and long GRB 050418
  35. GRB 050416b: Swift-BAT refined analysis
  36. GRB050416B: IR observations
  37. GRB 050416: Swift/UVOT refined analysis
  38. Swift-BAT detection of GRB 050416b
  39. GRB 050416: Swift/UVOT detection of afterglow emission
  40. GRB050416: Refined Swift-XRT analysis
  41. GRB 050416: Swift-BAT refined analysis
  42. GRB 050416: ART observations
  43. GRB 050416,optical observation
  44. GRB 050416: KAIT observations
  45. Swift BAT/XRT Detection of GRB 050416
  46. GRB 050412: optical limit
  47. GRB 050412: early Swift XRT analysis results
  48. GRB 050412: Swift-BAT refined analysis
  49. GRB 050412: Optical limit
  50. GRB 050412: Optical observations
  51. GRB050412: ROTSE-III Optical Limits
  52. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  53. GRB 050412: IR Observations
  54. GRB 050401: Optical limit
  55. GRB 050408: Optical limit
  56. GRB 050410, optical observations
  57. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  58. GRB 050410 R band Optical Observations
  59. GRB 050408: Swift XRT measurement of possible jet break
  60. GRB 050410: Early observations with Swift-UVOT
  61. Swift-BAT detection of GRB 050410
  62. GRB 050410: Swift XRT Position
  63. GRB 050408: Swift XRT analysis
  64. GRB 050408,optical observation
  65. GRB 050408: Magellan astrometry and photometry
  66. GRB 050408: ROTSE-III Optical Limits
  67. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  68. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  69. GRB 050406: early Swift XRT analysis results
  70. GRB 050406 BAT refined analysis
  71. GRB 050406: Early observations with Swift-UVOT
  72. Swift-BAT detection of GRB 050406
  73. Konus-Wind observation of GRB 050401
  74. GRB 050401 Optical Observations
  75. GRB 050401 BAT refined analysis
  76. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  77. GRB 050402: Early observations with Swift-UVOT
  78. Swift Trigger 113225: P60 Observations
  79. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  80. GRB 050401: Optical afterglow candidate
  81. Swift-BAT detection of GRB 050401
  82. Swift-BAT detection of GRB 050331b
  83. GRB 050331: Swift UVOT Source
  84. Konus-Wind observation of GRB 050326
  85. GRB050326: optical limit
  86. GRB 050326: Early observations with Swift-UVOT
  87. GRB 050326 : Planned XMM-Newton observation
  88. GRB 050326 BAT refined analysis
  89. Swift-BAT detection of a bright GRB 050326
  90. GRB050319, optical observations
  91. Swift-BAT detection of a bright outburst from SGR1806-20
  92. Swift-BAT trigger 112060 is not a real GRB
  93. GRB 050319: ROTSE-III Refined Analysis
  94. GRB 050319: Swift-UVOT detection of the afterglow
  95. GRB 050318: SWIFT-UVOT refined analysis
  96. GRB050319,optical observation
  97. GRB 050318: Swift/UVOT detection of afterglow emission
  98. RXTE Observations of GRB050318
  99. Swift-BAT detection of GRB 050318
  100. GRB 050315: Swift-BAT further refined analysis

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