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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"

19539 results found.

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

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