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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"

18618 results found.

  1. GRB 050412: ANU 2.3m observations
  2. GRB 050412: Early Optical/Ultraviolet Observations with
  3. GRB 050412: retraction of UVOT transient report
  4. GRB 050412: UVOT transient not in XRT error circle
  5. GRB 050412: Swift XRT Position
  6. GRB050412: optical limit before and during GRB
  7. GRB050412: ROTSE-III Optical Limits
  8. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  9. GRB 050412: IR Observations
  10. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  11. GRB 050410, optical observations
  12. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  13. GRB 050410 R band Optical Observations
  14. GRB050410 : Null detection report
  15. GRB 050410, optical observations
  16. GRB050410: Radio Observations
  17. GRB 050408: Swift XRT measurement of possible jet break
  18. GRB050410: MASTER optical observations
  19. GRB 050410: Early observations with Swift-UVOT
  20. Swift-BAT detection of GRB 050410
  21. GRB 050410: Swift XRT Position
  22. GRB 050408: Properties of the Host Galaxy
  23. GRB 050408: Swift XRT analysis
  24. GRB 050408, optical observations
  25. GRB050408: REM NIR and Optical observation
  26. GRB 050408 Optical Observations
  27. GRB 050408: Optical afterglow confirmed
  28. GRB 050408, optical observations
  29. GRB 050408 optical candidate
  30. GRB 050408: Swift XRT Position
  31. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  32. GRB 050406: early Swift XRT analysis results
  33. GRB 050406 BAT refined analysis
  34. GRB 050406: Early observations with Swift-UVOT
  35. GRB 050406: Swift XRT Position
  36. Swift-BAT detection of GRB 050406
  37. Konus-Wind observation of GRB 050401
  38. GRB050401: Radio observation at 610 MHz with GMRT
  39. GRB 050401: VLT spectroscopic redshift
  40. GRB 050401 Optical Observations
  41. GRB050401: Maidanak optical observation
  42. GRB 050401 BAT refined analysis
  43. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  44. GRB 050402A: IR Observations
  45. GRB 050402: Early observations with Swift-UVOT
  46. Swift Trigger 113225: P60 Observations
  47. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  48. GRB 050401: Optical afterglow candidate
  49. Swift-BAT detection of GRB 050401
  50. GRB 050401: Prompt XRT position
  51. Retraction of three Swift GRB triggers
  52. Swift-BAT detection of GRB 050331b
  53. GRB 050331: Swift UVOT Source
  54. Swift-BAT detection of GRB 050331
  55. GRB 050331: Swift XRT Position
  56. Swift Data Publicly Available Starting April 5, 2005
  57. Konus-Wind observation of GRB 050326
  58. GRB050326: optical limit
  59. GRB 050326: Early observations with Swift-UVOT
  60. GRB 050326 XMM-Newton observation
  61. GRB 050326 : Planned XMM-Newton observation
  62. GRB 050326: Swift XRT Position
  63. GRB050326: optical limit 33min before GRB
  64. GRB 050326 BAT refined analysis
  65. GRB050326: delayed XRT observation
  66. Swift-BAT detection of a bright GRB 050326
  67. GRB050319, optical observations
  68. GRB050319, color indices
  69. GRB050319: RTT150 Optical Observations
  70. Swift-BAT detection of a bright outburst from SGR1806-20
  71. Swift-BAT trigger 112060 is not a real GRB
  72. GRB 050319: ROTSE-III Refined Analysis
  73. GRB 050318: Swift-BAT refined analysis
  74. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  75. GRB 050319 R band observations
  76. GRB 050319: Swift-UVOT detection of the afterglow
  77. GRB 050315: Variability Analysis of Swift BAT Time History
  78. GRB050319: BR optical photometry
  79. GRB 050318: SWIFT-UVOT refined analysis
  80. GRB 050319: Swift-BAT refined analysis
  81. GRB050319,optical observation
  82. Swift Detection of GRB 050319
  83. GRB 050319: Detection of Possible Optical Counterpart
  84. GRB 050318: Swift/UVOT detection of afterglow emission
  85. GRB050318: Swift XRT position
  86. Swift-BAT detection of GRB 050318
  87. GRB050223: analysis of the XMM-Newton observation
  88. GRB 050306: ROTSE-III early limits
  89. GRB 050315: Swift-BAT further refined analysis
  90. GRB050315: Swift-BAT Refined analysis
  91. Non-detection of GRB050315 in ATCA Radio Observations
  92. GRB 050315: Swift XRT Position
  93. GRB 050315: Early Observations with Swift/UVOT
  94. Swift-BAT detection of GRB 050315
  95. GRB050223: No XMM-Newton OM detection of afterglow emission
  96. GRB050309: CONCAM pre-trigger and trigger coincident optical
  97. GRB 050126: Redshift determination
  98. Swift-BAT trigger 107873: No Swift XRT counterpart
  99. GRB 050306: Confirmation of X-ray afterglow
  100. GRB 050309, Early optical limits from RAPTOR

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