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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"

18629 results found.

  1. GRB 050416: Swift XRT Position
  2. GRB 050416: Radio observations
  3. Confirmation of OT for GRB050416
  4. GRB050416: P60 Afterglow Candidate
  5. Swift BAT/XRT Detection of GRB 050416
  6. GRB 050412: Subaru observations
  7. GRB 050412: optical limit
  8. GRB 050412: optical observations
  9. GRB 050408: refined XRT analysis, no jet break seen yet
  10. GRB 050412: early Swift XRT analysis results
  11. GRB 050412: Swift-BAT refined analysis
  12. GRB 050412: ANU 2.3m observations
  13. GRB 050412: Early Optical/Ultraviolet Observations with
  14. GRB 050412: retraction of UVOT transient report
  15. GRB 050412: UVOT transient not in XRT error circle
  16. GRB 050412: Swift XRT Position
  17. GRB050412: optical limit before and during GRB
  18. GRB050412: ROTSE-III Optical Limits
  19. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  20. GRB 050412: IR Observations
  21. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  22. GRB 050410, optical observations
  23. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  24. GRB 050410 R band Optical Observations
  25. GRB050410 : Null detection report
  26. GRB 050410, optical observations
  27. GRB050410: Radio Observations
  28. GRB 050408: Swift XRT measurement of possible jet break
  29. GRB050410: MASTER optical observations
  30. GRB 050410: Early observations with Swift-UVOT
  31. Swift-BAT detection of GRB 050410
  32. GRB 050410: Swift XRT Position
  33. GRB 050408: Properties of the Host Galaxy
  34. GRB 050408: Swift XRT analysis
  35. GRB 050408, optical observations
  36. GRB050408: REM NIR and Optical observation
  37. GRB 050408 Optical Observations
  38. GRB 050408: Optical afterglow confirmed
  39. GRB 050408, optical observations
  40. GRB 050408 optical candidate
  41. GRB 050408: Swift XRT Position
  42. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  43. GRB 050406: early Swift XRT analysis results
  44. GRB 050406 BAT refined analysis
  45. GRB 050406: Early observations with Swift-UVOT
  46. GRB 050406: Swift XRT Position
  47. Swift-BAT detection of GRB 050406
  48. Konus-Wind observation of GRB 050401
  49. GRB050401: Radio observation at 610 MHz with GMRT
  50. GRB 050401: VLT spectroscopic redshift
  51. GRB 050401 Optical Observations
  52. GRB050401: Maidanak optical observation
  53. GRB 050401 BAT refined analysis
  54. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  55. GRB 050402A: IR Observations
  56. GRB 050402: Early observations with Swift-UVOT
  57. Swift Trigger 113225: P60 Observations
  58. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  59. GRB 050401: Optical afterglow candidate
  60. Swift-BAT detection of GRB 050401
  61. GRB 050401: Prompt XRT position
  62. Retraction of three Swift GRB triggers
  63. Swift-BAT detection of GRB 050331b
  64. GRB 050331: Swift UVOT Source
  65. Swift-BAT detection of GRB 050331
  66. GRB 050331: Swift XRT Position
  67. Swift Data Publicly Available Starting April 5, 2005
  68. Konus-Wind observation of GRB 050326
  69. GRB050326: optical limit
  70. GRB 050326: Early observations with Swift-UVOT
  71. GRB 050326 XMM-Newton observation
  72. GRB 050326 : Planned XMM-Newton observation
  73. GRB 050326: Swift XRT Position
  74. GRB050326: optical limit 33min before GRB
  75. GRB 050326 BAT refined analysis
  76. GRB050326: delayed XRT observation
  77. Swift-BAT detection of a bright GRB 050326
  78. GRB050319, optical observations
  79. GRB050319, color indices
  80. GRB050319: RTT150 Optical Observations
  81. Swift-BAT detection of a bright outburst from SGR1806-20
  82. Swift-BAT trigger 112060 is not a real GRB
  83. GRB 050319: ROTSE-III Refined Analysis
  84. GRB 050318: Swift-BAT refined analysis
  85. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  86. GRB 050319 R band observations
  87. GRB 050319: Swift-UVOT detection of the afterglow
  88. GRB 050315: Variability Analysis of Swift BAT Time History
  89. GRB050319: BR optical photometry
  90. GRB 050318: SWIFT-UVOT refined analysis
  91. GRB 050319: Swift-BAT refined analysis
  92. GRB050319,optical observation
  93. Swift Detection of GRB 050319
  94. GRB 050319: Detection of Possible Optical Counterpart
  95. GRB 050318: Swift/UVOT detection of afterglow emission
  96. GRB050318: Swift XRT position
  97. Swift-BAT detection of GRB 050318
  98. GRB050223: analysis of the XMM-Newton observation
  99. GRB 050306: ROTSE-III early limits
  100. GRB 050315: Swift-BAT further refined analysis

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