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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"

19546 results found.

  1. GRB 050412: optical observations
  2. GRB 050408: refined XRT analysis, no jet break seen yet
  3. GRB 050412: early Swift XRT analysis results
  4. GRB 050412: Swift-BAT refined analysis
  5. GRB 050412: ANU 2.3m observations
  6. GRB 050412: Early Optical/Ultraviolet Observations with
  7. GRB 050412: retraction of UVOT transient report
  8. GRB 050412: UVOT transient not in XRT error circle
  9. GRB 050412: Swift XRT Position
  10. GRB050412: optical limit before and during GRB
  11. GRB050412: ROTSE-III Optical Limits
  12. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  13. GRB 050412: IR Observations
  14. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  15. GRB 050410, optical observations
  16. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  17. GRB 050410 R band Optical Observations
  18. GRB050410 : Null detection report
  19. GRB 050410, optical observations
  20. GRB050410: Radio Observations
  21. GRB 050408: Swift XRT measurement of possible jet break
  22. GRB050410: MASTER optical observations
  23. GRB 050410: Early observations with Swift-UVOT
  24. Swift-BAT detection of GRB 050410
  25. GRB 050410: Swift XRT Position
  26. GRB 050408: Properties of the Host Galaxy
  27. GRB 050408: Swift XRT analysis
  28. GRB 050408, optical observations
  29. GRB050408: REM NIR and Optical observation
  30. GRB 050408 Optical Observations
  31. GRB 050408: Optical afterglow confirmed
  32. GRB 050408, optical observations
  33. GRB 050408 optical candidate
  34. GRB 050408: Swift XRT Position
  35. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  36. GRB 050406: early Swift XRT analysis results
  37. GRB 050406 BAT refined analysis
  38. GRB 050406: Early observations with Swift-UVOT
  39. GRB 050406: Swift XRT Position
  40. Swift-BAT detection of GRB 050406
  41. Konus-Wind observation of GRB 050401
  42. GRB050401: Radio observation at 610 MHz with GMRT
  43. GRB 050401: VLT spectroscopic redshift
  44. GRB 050401 Optical Observations
  45. GRB050401: Maidanak optical observation
  46. GRB 050401 BAT refined analysis
  47. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  48. GRB 050402A: IR Observations
  49. GRB 050402: Early observations with Swift-UVOT
  50. Swift Trigger 113225: P60 Observations
  51. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  52. GRB 050401: Optical afterglow candidate
  53. Swift-BAT detection of GRB 050401
  54. GRB 050401: Prompt XRT position
  55. Retraction of three Swift GRB triggers
  56. Swift-BAT detection of GRB 050331b
  57. GRB 050331: Swift UVOT Source
  58. Swift-BAT detection of GRB 050331
  59. GRB 050331: Swift XRT Position
  60. Swift Data Publicly Available Starting April 5, 2005
  61. Konus-Wind observation of GRB 050326
  62. GRB050326: optical limit
  63. GRB 050326: Early observations with Swift-UVOT
  64. GRB 050326 XMM-Newton observation
  65. GRB 050326 : Planned XMM-Newton observation
  66. GRB 050326: Swift XRT Position
  67. GRB050326: optical limit 33min before GRB
  68. GRB 050326 BAT refined analysis
  69. GRB050326: delayed XRT observation
  70. Swift-BAT detection of a bright GRB 050326
  71. GRB050319, optical observations
  72. GRB050319, color indices
  73. GRB050319: RTT150 Optical Observations
  74. Swift-BAT detection of a bright outburst from SGR1806-20
  75. Swift-BAT trigger 112060 is not a real GRB
  76. GRB 050319: ROTSE-III Refined Analysis
  77. GRB 050318: Swift-BAT refined analysis
  78. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  79. GRB 050319 R band observations
  80. GRB 050319: Swift-UVOT detection of the afterglow
  81. GRB 050315: Variability Analysis of Swift BAT Time History
  82. GRB050319: BR optical photometry
  83. GRB 050318: SWIFT-UVOT refined analysis
  84. GRB 050319: Swift-BAT refined analysis
  85. GRB050319,optical observation
  86. Swift Detection of GRB 050319
  87. GRB 050319: Detection of Possible Optical Counterpart
  88. GRB 050318: Swift/UVOT detection of afterglow emission
  89. GRB050318: Swift XRT position
  90. Swift-BAT detection of GRB 050318
  91. GRB050223: analysis of the XMM-Newton observation
  92. GRB 050306: ROTSE-III early limits
  93. GRB 050315: Swift-BAT further refined analysis
  94. GRB050315: Swift-BAT Refined analysis
  95. Non-detection of GRB050315 in ATCA Radio Observations
  96. GRB 050315: Swift XRT Position
  97. GRB 050315: Early Observations with Swift/UVOT
  98. Swift-BAT detection of GRB 050315
  99. GRB050223: No XMM-Newton OM detection of afterglow emission
  100. GRB050309: CONCAM pre-trigger and trigger coincident optical

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