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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"

19609 results found.

  1. GRB 091102 : Faulkes Telescope South Upper Limits
  2. GRB 091102A: Fermi GBM observation
  3. GRB 091102: Swift-XRT refined analysis
  4. GRB 091102: Swift/UVOT Upper Limits
  5. GRB 091102: GROND Upper Limits
  6. GRB 091102: Swift-BAT refined analysis
  7. GRB 091102: Swift/XRT localization
  8. GRB 091102: ROTSE-III Optical Limits
  9. GRB 091102: Swift/UVOT Finding Chart Observation
  10. GRB 091102: Swift detection of a burst
  11. GRB 091024: optical observations
  12. GRB 091024: Fermi LAT upper limits
  13. GRB 090920: Skynet/DSO Detection
  14. GRB091029: Swift/UVOT observations
  15. GRB 091029: Swift XRT refined analysis
  16. GRB 091029: Swift-BAT refined analysis
  17. GRB 091029: Enhanced Swift-XRT position
  18. GRB 091029: Skynet/PROMPT Observations of Peak and Fading
  19. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  20. GRB 091029: Swift detection of a burst with an optical counterpart
  21. A mistake in testing a new function in Swift
  22. GRB 091020: Fermi GBM observation
  23. GRB 091026: Suzaku WAM observation of the prompt emission
  24. GRB 091026: GROND Upper Limits
  25. GRB 091020: Late TLS detection
  26. GRB 091026: Swift-BAT refined analysis
  27. Radio afterglow detection from GRB 091020
  28. GRB 091026: Swift/UVOT Upper Limits
  29. GRB 091024: Burst was outside the Swift-BAT FOV after T0(BAT)+460sec
  30. GRB 091026: Swift-XRT refined analysis
  31. GRB 091026: Enhanced Swift-XRT position
  32. Konus-Wind and Konus-RF observations of GRB 091024
  33. GRB 091026: Updated Swift-XRT position
  34. GRB 091026: Swift detection of a Gamma Ray Burst
  35. Swift-BAT Triggers 373776-373778 are not real
  36. GRB091024 Swift/UVOT Upper Limits
  37. GRB 091024: TLS Upper Limit
  38. GRB 091020: Early TLS Multicolor detections, red afterglow
  39. GRB 091024: KAIT optical afterglow observations
  40. GRB 091024: Swift-BAT refined analysis
  41. Swift-BAT Triggers 373679-373684 are not real
  42. GRB 091024: Fermi GBM Observations
  43. GRB 091024: Swift-XRT team refined analysis
  44. Swift-BAT trigger 373691 is a galactic bulge transient
  45. GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
  46. GRB 091024: Faulkes Telescope North Afterglow Candidate
  47. GRB 091024: Swift detection of a burst
  48. GRB 091020: Swift-XRT refined analysis
  49. GRB 091018: Swift XRT refined analysis
  50. GRB091020 Swift/UVOT observations
  51. GRB 091020, Swift-BAT refined analysis
  52. GRB 091020: Enhanced Swift-XRT position
  53. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  54. GRB 091020: Swift detection of a burst with an optical afterglow
  55. GRB 091018: Skynet/PROMPT Observations of Fading
  56. Konus-RF observation of GRB 091018
  57. GRB 091018 : Faulkes Telescope South Observations
  58. GRB091018: Swift/UVOT observations
  59. GRB 091018: Swift-BAT refined analysis
  60. GRB 091018: Enhanced Swift-XRT position
  61. GRB 091018: ROTSE-III Detection of Optical Counterpart
  62. GRB 091018: Swift detection of a burst with optical afterglow
  63. GRB 090726 R band observations
  64. GRB 091010: Swift-XRT refined analysis
  65. Radio observation of GRB090927 with ATCA
  66. GRB 091010: Fermi GBM observation
  67. GRB 090531A: Skynet/PROMPT Observations
  68. GRB 090530A: Skynet/DSO Detections
  69. GRB 091010: Enhanced XRT position
  70. GRB 091010: GROND afterglow candidate
  71. GRB 091010: Swift/UVOT Upper Limits
  72. GRB 091010: Swift-XRT position
  73. GRB 090518: Skynet/PROMPT Observations
  74. Short-Duration GRB 090621: Skynet/Dolomiti Observations
  75. GRB 090812: Skynet/PROMPT and GORT Observations
  76. GRB 091003: Lick observations and possible SDSS host galaxy
  77. GRB 090926B: Skynet/PROMPT Observations
  78. GRB 090929B: Suzaku WAM observation of the prompt emission
  79. GRB 091003: Swift-XRT confirmation of fading afterglow
  80. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  81. GRB 091003: UVOT-enhanced XRT position
  82. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  83. GRB 091003: Swift XRT analysis
  84. GRB 091003A: Fermi LAT detection
  85. GRB 090929A: Swift/UVOT Observations
  86. GRB 090929A, Swift-BAT refined analysis
  87. GRB 090929B, Swift-BAT refined analysis
  88. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  89. GRB 090929A: Swift-XRT non-detection
  90. Konus-Wind observation of GRB 090929A
  91. Konus-Wind observation of GRB 090929B
  92. GRB 090927: Fermi GBM observation
  93. GRB 090929B: Swift-XRT refined analysis
  94. GRB 090929B: Skynet/DSO Observations
  95. GRB 090929B: Swift/UVOT Observations
  96. Konus-RF observation of GRB 090929A
  97. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  98. GRB 090929A BAT location of the Fermi GBM burst
  99. Correction: GRB 090929B: Enhanced Swift-XRT position
  100. GRB 090929: Enhanced Swift-XRT position

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