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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"

18833 results found.

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

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