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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"

21459 results found.

  1. GRB 050416,optical observation
  2. GRB 050416: KAIT observations
  3. GRB 050416: Swift XRT Position
  4. GRB 050416: Radio observations
  5. Confirmation of OT for GRB050416
  6. GRB050416: P60 Afterglow Candidate
  7. Swift BAT/XRT Detection of GRB 050416
  8. GRB 050412: Subaru observations
  9. GRB 050412: PROMPT VRcIc Observations
  10. GRB 050412: optical limit
  11. GRB 050412: optical observations
  12. GRB 050408: refined XRT analysis, no jet break seen yet
  13. GRB 050412: early Swift XRT analysis results
  14. GRB 050412 : XingLong optical observation
  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: LCO Optical Observations
  21. GRB 050412: Optical observations
  22. GRB050412: P60 Observations
  23. GRB 050412: Swift XRT Position
  24. GRB050412: optical limit before and during GRB
  25. GRB050412: ROTSE-III Optical Limits
  26. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  27. GRB 050412: IR Observations
  28. GRB050410: P60 Observations
  29. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  30. GRB 050410, optical observations
  31. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  32. GRB 050410 R band Optical Observations
  33. GRB050410 : Null detection report
  34. GRB 050410, optical observations
  35. GRB050410: Radio Observations
  36. GRB 050408: Swift XRT measurement of possible jet break
  37. GRB050410: MASTER optical observations
  38. GRB 050410: Early observations with Swift-UVOT
  39. Swift-BAT detection of GRB 050410
  40. GRB 050410: Swift XRT Position
  41. GRB 050408: Properties of the Host Galaxy
  42. GRB 050408: Swift XRT analysis
  43. GRB 050408, optical observations
  44. GRB050408: REM NIR and Optical observation
  45. GRB 050408 Optical Observations
  46. GRB 050408: Optical afterglow confirmed
  47. GRB 050408, optical observations
  48. GRB 050408 optical candidate
  49. GRB 050408: Swift XRT Position
  50. GRB050401: Radio Detection
  51. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  52. GRB 050406: Magellan optical observations
  53. GRB 050406: early Swift XRT analysis results
  54. GRB 050406 BAT refined analysis
  55. GRB 050406: Early observations with Swift-UVOT
  56. GRB 050406: Swift XRT Position
  57. Swift-BAT detection of GRB 050406
  58. Konus-Wind observation of GRB 050401
  59. GRB050401: Radio observation at 610 MHz with GMRT
  60. GRB 050401: VLT spectroscopic redshift
  61. GRB 050401 Optical Observations
  62. GRB050401: Maidanak optical observation
  63. GRB 050401 BAT refined analysis
  64. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  65. GRB 050402A: IR Observations
  66. GRB 050402: Early observations with Swift-UVOT
  67. Swift Trigger 113225: P60 Observations
  68. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  69. GRB 050401: Optical afterglow candidate
  70. Swift-BAT detection of GRB 050401
  71. GRB 050401: Prompt XRT position
  72. Retraction of three Swift GRB triggers
  73. GRB050331: No Afterglow Detected
  74. Swift-BAT detection of GRB 050331b
  75. GRB 050331: Swift UVOT Source
  76. Swift-BAT detection of GRB 050331
  77. GRB 050331: Swift XRT Position
  78. Swift Data Publicly Available Starting April 5, 2005
  79. Konus-Wind observation of GRB 050326
  80. GRB050326: optical limit
  81. GRB 050326: Early observations with Swift-UVOT
  82. GRB 050326 XMM-Newton observation
  83. GRB 050326 : Planned XMM-Newton observation
  84. GRB 050326: Swift XRT Position
  85. GRB050326: optical limit 33min before GRB
  86. GRB 050326 BAT refined analysis
  87. GRB050326: delayed XRT observation
  88. Swift-BAT detection of a bright GRB 050326
  89. GRB050319, optical observations
  90. GRB050319, color indices
  91. GRB050319: RTT150 Optical Observations
  92. Swift-BAT detection of a bright outburst from SGR1806-20
  93. Swift-BAT trigger 112060 is not a real GRB
  94. GRB 050319: ROTSE-III Refined Analysis
  95. GRB 050318: Swift-BAT refined analysis
  96. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  97. GRB 050319 R band observations
  98. GRB 050319: Swift-UVOT detection of the afterglow
  99. GRB 050315: Variability Analysis of Swift BAT Time History
  100. GRB050319: BR optical photometry

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