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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"

19530 results found.

  1. GRB 050416: KAIT observations
  2. GRB 050416: Swift XRT Position
  3. GRB 050416: Radio observations
  4. Confirmation of OT for GRB050416
  5. GRB050416: P60 Afterglow Candidate
  6. Swift BAT/XRT Detection of GRB 050416
  7. GRB 050412: Subaru observations
  8. GRB 050412: optical limit
  9. GRB 050412: optical observations
  10. GRB 050408: refined XRT analysis, no jet break seen yet
  11. GRB 050412: early Swift XRT analysis results
  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: Swift XRT Position
  18. GRB050412: optical limit before and during GRB
  19. GRB050412: ROTSE-III Optical Limits
  20. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  21. GRB 050412: IR Observations
  22. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  23. GRB 050410, optical observations
  24. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  25. GRB 050410 R band Optical Observations
  26. GRB050410 : Null detection report
  27. GRB 050410, optical observations
  28. GRB050410: Radio Observations
  29. GRB 050408: Swift XRT measurement of possible jet break
  30. GRB050410: MASTER optical observations
  31. GRB 050410: Early observations with Swift-UVOT
  32. Swift-BAT detection of GRB 050410
  33. GRB 050410: Swift XRT Position
  34. GRB 050408: Properties of the Host Galaxy
  35. GRB 050408: Swift XRT analysis
  36. GRB 050408, optical observations
  37. GRB050408: REM NIR and Optical observation
  38. GRB 050408 Optical Observations
  39. GRB 050408: Optical afterglow confirmed
  40. GRB 050408, optical observations
  41. GRB 050408 optical candidate
  42. GRB 050408: Swift XRT Position
  43. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  44. GRB 050406: early Swift XRT analysis results
  45. GRB 050406 BAT refined analysis
  46. GRB 050406: Early observations with Swift-UVOT
  47. GRB 050406: Swift XRT Position
  48. Swift-BAT detection of GRB 050406
  49. Konus-Wind observation of GRB 050401
  50. GRB050401: Radio observation at 610 MHz with GMRT
  51. GRB 050401: VLT spectroscopic redshift
  52. GRB 050401 Optical Observations
  53. GRB050401: Maidanak optical observation
  54. GRB 050401 BAT refined analysis
  55. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  56. GRB 050402A: IR Observations
  57. GRB 050402: Early observations with Swift-UVOT
  58. Swift Trigger 113225: P60 Observations
  59. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  60. GRB 050401: Optical afterglow candidate
  61. Swift-BAT detection of GRB 050401
  62. GRB 050401: Prompt XRT position
  63. Retraction of three Swift GRB triggers
  64. Swift-BAT detection of GRB 050331b
  65. GRB 050331: Swift UVOT Source
  66. Swift-BAT detection of GRB 050331
  67. GRB 050331: Swift XRT Position
  68. Swift Data Publicly Available Starting April 5, 2005
  69. Konus-Wind observation of GRB 050326
  70. GRB050326: optical limit
  71. GRB 050326: Early observations with Swift-UVOT
  72. GRB 050326 XMM-Newton observation
  73. GRB 050326 : Planned XMM-Newton observation
  74. GRB 050326: Swift XRT Position
  75. GRB050326: optical limit 33min before GRB
  76. GRB 050326 BAT refined analysis
  77. GRB050326: delayed XRT observation
  78. Swift-BAT detection of a bright GRB 050326
  79. GRB050319, optical observations
  80. GRB050319, color indices
  81. GRB050319: RTT150 Optical Observations
  82. Swift-BAT detection of a bright outburst from SGR1806-20
  83. Swift-BAT trigger 112060 is not a real GRB
  84. GRB 050319: ROTSE-III Refined Analysis
  85. GRB 050318: Swift-BAT refined analysis
  86. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  87. GRB 050319 R band observations
  88. GRB 050319: Swift-UVOT detection of the afterglow
  89. GRB 050315: Variability Analysis of Swift BAT Time History
  90. GRB050319: BR optical photometry
  91. GRB 050318: SWIFT-UVOT refined analysis
  92. GRB 050319: Swift-BAT refined analysis
  93. GRB050319,optical observation
  94. Swift Detection of GRB 050319
  95. GRB 050319: Detection of Possible Optical Counterpart
  96. GRB 050318: Swift/UVOT detection of afterglow emission
  97. GRB050318: Swift XRT position
  98. Swift-BAT detection of GRB 050318
  99. GRB050223: analysis of the XMM-Newton observation
  100. GRB 050306: ROTSE-III early limits

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