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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"

21456 results found.

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

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