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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"

19534 results found.

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

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