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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"

18541 results found.

  1. Swift-BAT detection of the bright and long GRB 050418
  2. GRB 050416B: optical observations
  3. GRB 050416b: Swift-BAT refined analysis
  4. GRB 050416: Swift/UVOT refined analysis
  5. Swift-BAT detection of GRB 050416b
  6. GRB050412: Radio Observations
  7. GRB 050416: Swift/UVOT detection of afterglow emission
  8. GRB050416: Refined Swift-XRT analysis
  9. GRB050416: Maidanak optical observations
  10. GRB 050416: Swift-BAT refined analysis
  11. GRB 050416,optical observation
  12. GRB 050416: KAIT observations
  13. GRB 050416: Swift XRT Position
  14. GRB 050416: Radio observations
  15. Confirmation of OT for GRB050416
  16. GRB050416: P60 Afterglow Candidate
  17. Swift BAT/XRT Detection of GRB 050416
  18. GRB 050412: Subaru observations
  19. GRB 050412: optical limit
  20. GRB 050412: optical observations
  21. GRB 050408: refined XRT analysis, no jet break seen yet
  22. GRB 050412: early Swift XRT analysis results
  23. GRB 050412: Swift-BAT refined analysis
  24. GRB 050412: ANU 2.3m observations
  25. GRB 050412: Early Optical/Ultraviolet Observations with
  26. GRB 050412: retraction of UVOT transient report
  27. GRB 050412: UVOT transient not in XRT error circle
  28. GRB 050412: Swift XRT Position
  29. GRB050412: optical limit before and during GRB
  30. GRB050412: ROTSE-III Optical Limits
  31. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  32. GRB 050412: IR Observations
  33. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  34. GRB 050410, optical observations
  35. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  36. GRB 050410 R band Optical Observations
  37. GRB050410 : Null detection report
  38. GRB 050410, optical observations
  39. GRB050410: Radio Observations
  40. GRB 050408: Swift XRT measurement of possible jet break
  41. GRB050410: MASTER optical observations
  42. GRB 050410: Early observations with Swift-UVOT
  43. Swift-BAT detection of GRB 050410
  44. GRB 050410: Swift XRT Position
  45. GRB 050408: Properties of the Host Galaxy
  46. GRB 050408: Swift XRT analysis
  47. GRB 050408, optical observations
  48. GRB050408: REM NIR and Optical observation
  49. GRB 050408 Optical Observations
  50. GRB 050408: Optical afterglow confirmed
  51. GRB 050408, optical observations
  52. GRB 050408 optical candidate
  53. GRB 050408: Swift XRT Position
  54. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  55. GRB 050406: early Swift XRT analysis results
  56. GRB 050406 BAT refined analysis
  57. GRB 050406: Early observations with Swift-UVOT
  58. GRB 050406: Swift XRT Position
  59. Swift-BAT detection of GRB 050406
  60. Konus-Wind observation of GRB 050401
  61. GRB050401: Radio observation at 610 MHz with GMRT
  62. GRB 050401: VLT spectroscopic redshift
  63. GRB 050401 Optical Observations
  64. GRB050401: Maidanak optical observation
  65. GRB 050401 BAT refined analysis
  66. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  67. GRB 050402A: IR Observations
  68. GRB 050402: Early observations with Swift-UVOT
  69. Swift Trigger 113225: P60 Observations
  70. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  71. GRB 050401: Optical afterglow candidate
  72. Swift-BAT detection of GRB 050401
  73. GRB 050401: Prompt XRT position
  74. Retraction of three Swift GRB triggers
  75. Swift-BAT detection of GRB 050331b
  76. GRB 050331: Swift UVOT Source
  77. Swift-BAT detection of GRB 050331
  78. GRB 050331: Swift XRT Position
  79. Swift Data Publicly Available Starting April 5, 2005
  80. Konus-Wind observation of GRB 050326
  81. GRB050326: optical limit
  82. GRB 050326: Early observations with Swift-UVOT
  83. GRB 050326 XMM-Newton observation
  84. GRB 050326 : Planned XMM-Newton observation
  85. GRB 050326: Swift XRT Position
  86. GRB050326: optical limit 33min before GRB
  87. GRB 050326 BAT refined analysis
  88. GRB050326: delayed XRT observation
  89. Swift-BAT detection of a bright GRB 050326
  90. GRB050319, optical observations
  91. GRB050319, color indices
  92. GRB050319: RTT150 Optical Observations
  93. Swift-BAT detection of a bright outburst from SGR1806-20
  94. Swift-BAT trigger 112060 is not a real GRB
  95. GRB 050319: ROTSE-III Refined Analysis
  96. GRB 050318: Swift-BAT refined analysis
  97. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  98. GRB 050319 R band observations
  99. GRB 050319: Swift-UVOT detection of the afterglow
  100. GRB 050315: Variability Analysis of Swift BAT Time History

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