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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"

21455 results found.

  1. Confirmation of OT for GRB050416
  2. GRB050416: P60 Afterglow Candidate
  3. Swift BAT/XRT Detection of GRB 050416
  4. GRB 050412: Subaru observations
  5. GRB 050412: PROMPT VRcIc Observations
  6. GRB 050412: optical limit
  7. GRB 050412: optical observations
  8. GRB 050408: refined XRT analysis, no jet break seen yet
  9. GRB 050412: early Swift XRT analysis results
  10. GRB 050412 : XingLong optical observation
  11. GRB 050412: Swift-BAT refined analysis
  12. GRB 050412: ANU 2.3m observations
  13. GRB 050412: Early Optical/Ultraviolet Observations with
  14. GRB 050412: retraction of UVOT transient report
  15. GRB 050412: UVOT transient not in XRT error circle
  16. GRB 050412: LCO Optical Observations
  17. GRB 050412: Optical observations
  18. GRB050412: P60 Observations
  19. GRB 050412: Swift XRT Position
  20. GRB050412: optical limit before and during GRB
  21. GRB050412: ROTSE-III Optical Limits
  22. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  23. GRB 050412: IR Observations
  24. GRB050410: P60 Observations
  25. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  26. GRB 050410, optical observations
  27. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  28. GRB 050410 R band Optical Observations
  29. GRB050410 : Null detection report
  30. GRB 050410, optical observations
  31. GRB050410: Radio Observations
  32. GRB 050408: Swift XRT measurement of possible jet break
  33. GRB050410: MASTER optical observations
  34. GRB 050410: Early observations with Swift-UVOT
  35. Swift-BAT detection of GRB 050410
  36. GRB 050410: Swift XRT Position
  37. GRB 050408: Properties of the Host Galaxy
  38. GRB 050408: Swift XRT analysis
  39. GRB 050408, optical observations
  40. GRB050408: REM NIR and Optical observation
  41. GRB 050408 Optical Observations
  42. GRB 050408: Optical afterglow confirmed
  43. GRB 050408, optical observations
  44. GRB 050408 optical candidate
  45. GRB 050408: Swift XRT Position
  46. GRB050401: Radio Detection
  47. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  48. GRB 050406: Magellan optical observations
  49. GRB 050406: early Swift XRT analysis results
  50. GRB 050406 BAT refined analysis
  51. GRB 050406: Early observations with Swift-UVOT
  52. GRB 050406: Swift XRT Position
  53. Swift-BAT detection of GRB 050406
  54. Konus-Wind observation of GRB 050401
  55. GRB050401: Radio observation at 610 MHz with GMRT
  56. GRB 050401: VLT spectroscopic redshift
  57. GRB 050401 Optical Observations
  58. GRB050401: Maidanak optical observation
  59. GRB 050401 BAT refined analysis
  60. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  61. GRB 050402A: IR Observations
  62. GRB 050402: Early observations with Swift-UVOT
  63. Swift Trigger 113225: P60 Observations
  64. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  65. GRB 050401: Optical afterglow candidate
  66. Swift-BAT detection of GRB 050401
  67. GRB 050401: Prompt XRT position
  68. Retraction of three Swift GRB triggers
  69. GRB050331: No Afterglow Detected
  70. Swift-BAT detection of GRB 050331b
  71. GRB 050331: Swift UVOT Source
  72. Swift-BAT detection of GRB 050331
  73. GRB 050331: Swift XRT Position
  74. Swift Data Publicly Available Starting April 5, 2005
  75. Konus-Wind observation of GRB 050326
  76. GRB050326: optical limit
  77. GRB 050326: Early observations with Swift-UVOT
  78. GRB 050326 XMM-Newton observation
  79. GRB 050326 : Planned XMM-Newton observation
  80. GRB 050326: Swift XRT Position
  81. GRB050326: optical limit 33min before GRB
  82. GRB 050326 BAT refined analysis
  83. GRB050326: delayed XRT observation
  84. Swift-BAT detection of a bright GRB 050326
  85. GRB050319, optical observations
  86. GRB050319, color indices
  87. GRB050319: RTT150 Optical Observations
  88. Swift-BAT detection of a bright outburst from SGR1806-20
  89. Swift-BAT trigger 112060 is not a real GRB
  90. GRB 050319: ROTSE-III Refined Analysis
  91. GRB 050318: Swift-BAT refined analysis
  92. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  93. GRB 050319 R band observations
  94. GRB 050319: Swift-UVOT detection of the afterglow
  95. GRB 050315: Variability Analysis of Swift BAT Time History
  96. GRB050319: BR optical photometry
  97. GRB 050318: SWIFT-UVOT refined analysis
  98. GRB 050319: Swift-BAT refined analysis
  99. GRB050319,optical observation
  100. Swift Detection of GRB 050319

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