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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"

19342 results found.

  1. GRB 050418: Swift-BAT refined analysis
  2. Swift-BAT detection of the bright and long GRB 050418
  3. GRB 050416B: optical observations
  4. GRB 050416b: Swift-BAT refined analysis
  5. GRB 050416: Swift/UVOT refined analysis
  6. Swift-BAT detection of GRB 050416b
  7. GRB050412: Radio Observations
  8. GRB 050416: Swift/UVOT detection of afterglow emission
  9. GRB050416: Refined Swift-XRT analysis
  10. GRB050416: Maidanak optical observations
  11. GRB 050416: Swift-BAT refined analysis
  12. GRB 050416,optical observation
  13. GRB 050416: KAIT observations
  14. GRB 050416: Swift XRT Position
  15. GRB 050416: Radio observations
  16. Confirmation of OT for GRB050416
  17. GRB050416: P60 Afterglow Candidate
  18. Swift BAT/XRT Detection of GRB 050416
  19. GRB 050412: Subaru observations
  20. GRB 050412: optical limit
  21. GRB 050412: optical observations
  22. GRB 050408: refined XRT analysis, no jet break seen yet
  23. GRB 050412: early Swift XRT analysis results
  24. GRB 050412: Swift-BAT refined analysis
  25. GRB 050412: ANU 2.3m observations
  26. GRB 050412: Early Optical/Ultraviolet Observations with
  27. GRB 050412: retraction of UVOT transient report
  28. GRB 050412: UVOT transient not in XRT error circle
  29. GRB 050412: Swift XRT Position
  30. GRB050412: optical limit before and during GRB
  31. GRB050412: ROTSE-III Optical Limits
  32. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  33. GRB 050412: IR Observations
  34. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  35. GRB 050410, optical observations
  36. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  37. GRB 050410 R band Optical Observations
  38. GRB050410 : Null detection report
  39. GRB 050410, optical observations
  40. GRB050410: Radio Observations
  41. GRB 050408: Swift XRT measurement of possible jet break
  42. GRB050410: MASTER optical observations
  43. GRB 050410: Early observations with Swift-UVOT
  44. Swift-BAT detection of GRB 050410
  45. GRB 050410: Swift XRT Position
  46. GRB 050408: Properties of the Host Galaxy
  47. GRB 050408: Swift XRT analysis
  48. GRB 050408, optical observations
  49. GRB050408: REM NIR and Optical observation
  50. GRB 050408 Optical Observations
  51. GRB 050408: Optical afterglow confirmed
  52. GRB 050408, optical observations
  53. GRB 050408 optical candidate
  54. GRB 050408: Swift XRT Position
  55. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  56. GRB 050406: early Swift XRT analysis results
  57. GRB 050406 BAT refined analysis
  58. GRB 050406: Early observations with Swift-UVOT
  59. GRB 050406: Swift XRT Position
  60. Swift-BAT detection of GRB 050406
  61. Konus-Wind observation of GRB 050401
  62. GRB050401: Radio observation at 610 MHz with GMRT
  63. GRB 050401: VLT spectroscopic redshift
  64. GRB 050401 Optical Observations
  65. GRB050401: Maidanak optical observation
  66. GRB 050401 BAT refined analysis
  67. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  68. GRB 050402A: IR Observations
  69. GRB 050402: Early observations with Swift-UVOT
  70. Swift Trigger 113225: P60 Observations
  71. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  72. GRB 050401: Optical afterglow candidate
  73. Swift-BAT detection of GRB 050401
  74. GRB 050401: Prompt XRT position
  75. Retraction of three Swift GRB triggers
  76. Swift-BAT detection of GRB 050331b
  77. GRB 050331: Swift UVOT Source
  78. Swift-BAT detection of GRB 050331
  79. GRB 050331: Swift XRT Position
  80. Swift Data Publicly Available Starting April 5, 2005
  81. Konus-Wind observation of GRB 050326
  82. GRB050326: optical limit
  83. GRB 050326: Early observations with Swift-UVOT
  84. GRB 050326 XMM-Newton observation
  85. GRB 050326 : Planned XMM-Newton observation
  86. GRB 050326: Swift XRT Position
  87. GRB050326: optical limit 33min before GRB
  88. GRB 050326 BAT refined analysis
  89. GRB050326: delayed XRT observation
  90. Swift-BAT detection of a bright GRB 050326
  91. GRB050319, optical observations
  92. GRB050319, color indices
  93. GRB050319: RTT150 Optical Observations
  94. Swift-BAT detection of a bright outburst from SGR1806-20
  95. Swift-BAT trigger 112060 is not a real GRB
  96. GRB 050319: ROTSE-III Refined Analysis
  97. GRB 050318: Swift-BAT refined analysis
  98. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  99. GRB 050319 R band observations
  100. GRB 050319: Swift-UVOT detection of the afterglow

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