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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"

19607 results found.

  1. GRB 091102: Swift-XRT refined analysis
  2. GRB 091102: Swift/UVOT Upper Limits
  3. GRB 091102: GROND Upper Limits
  4. GRB 091102: Swift-BAT refined analysis
  5. GRB 091102: Swift/XRT localization
  6. GRB 091102: ROTSE-III Optical Limits
  7. GRB 091102: Swift/UVOT Finding Chart Observation
  8. GRB 091102: Swift detection of a burst
  9. GRB 091024: optical observations
  10. GRB 091024: Fermi LAT upper limits
  11. GRB 090920: Skynet/DSO Detection
  12. GRB091029: Swift/UVOT observations
  13. GRB 091029: Swift XRT refined analysis
  14. GRB 091029: Swift-BAT refined analysis
  15. GRB 091029: Enhanced Swift-XRT position
  16. GRB 091029: Skynet/PROMPT Observations of Peak and Fading
  17. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  18. GRB 091029: Swift detection of a burst with an optical counterpart
  19. A mistake in testing a new function in Swift
  20. GRB 091020: Fermi GBM observation
  21. GRB 091026: Suzaku WAM observation of the prompt emission
  22. GRB 091026: GROND Upper Limits
  23. GRB 091020: Late TLS detection
  24. GRB 091026: Swift-BAT refined analysis
  25. Radio afterglow detection from GRB 091020
  26. GRB 091026: Swift/UVOT Upper Limits
  27. GRB 091024: Burst was outside the Swift-BAT FOV after T0(BAT)+460sec
  28. GRB 091026: Swift-XRT refined analysis
  29. GRB 091026: Enhanced Swift-XRT position
  30. Konus-Wind and Konus-RF observations of GRB 091024
  31. GRB 091026: Updated Swift-XRT position
  32. GRB 091026: Swift detection of a Gamma Ray Burst
  33. Swift-BAT Triggers 373776-373778 are not real
  34. GRB091024 Swift/UVOT Upper Limits
  35. GRB 091024: TLS Upper Limit
  36. GRB 091020: Early TLS Multicolor detections, red afterglow
  37. GRB 091024: KAIT optical afterglow observations
  38. GRB 091024: Swift-BAT refined analysis
  39. Swift-BAT Triggers 373679-373684 are not real
  40. GRB 091024: Fermi GBM Observations
  41. GRB 091024: Swift-XRT team refined analysis
  42. Swift-BAT trigger 373691 is a galactic bulge transient
  43. GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
  44. GRB 091024: Faulkes Telescope North Afterglow Candidate
  45. GRB 091024: Swift detection of a burst
  46. GRB 091020: Swift-XRT refined analysis
  47. GRB 091018: Swift XRT refined analysis
  48. GRB091020 Swift/UVOT observations
  49. GRB 091020, Swift-BAT refined analysis
  50. GRB 091020: Enhanced Swift-XRT position
  51. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  52. GRB 091020: Swift detection of a burst with an optical afterglow
  53. GRB 091018: Skynet/PROMPT Observations of Fading
  54. Konus-RF observation of GRB 091018
  55. GRB 091018 : Faulkes Telescope South Observations
  56. GRB091018: Swift/UVOT observations
  57. GRB 091018: Swift-BAT refined analysis
  58. GRB 091018: Enhanced Swift-XRT position
  59. GRB 091018: ROTSE-III Detection of Optical Counterpart
  60. GRB 091018: Swift detection of a burst with optical afterglow
  61. GRB 090726 R band observations
  62. GRB 091010: Swift-XRT refined analysis
  63. Radio observation of GRB090927 with ATCA
  64. GRB 091010: Fermi GBM observation
  65. GRB 090531A: Skynet/PROMPT Observations
  66. GRB 090530A: Skynet/DSO Detections
  67. GRB 091010: Enhanced XRT position
  68. GRB 091010: GROND afterglow candidate
  69. GRB 091010: Swift/UVOT Upper Limits
  70. GRB 091010: Swift-XRT position
  71. GRB 090518: Skynet/PROMPT Observations
  72. Short-Duration GRB 090621: Skynet/Dolomiti Observations
  73. GRB 090812: Skynet/PROMPT and GORT Observations
  74. GRB 091003: Lick observations and possible SDSS host galaxy
  75. GRB 090926B: Skynet/PROMPT Observations
  76. GRB 090929B: Suzaku WAM observation of the prompt emission
  77. GRB 091003: Swift-XRT confirmation of fading afterglow
  78. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  79. GRB 091003: UVOT-enhanced XRT position
  80. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  81. GRB 091003: Swift XRT analysis
  82. GRB 091003A: Fermi LAT detection
  83. GRB 090929A: Swift/UVOT Observations
  84. GRB 090929A, Swift-BAT refined analysis
  85. GRB 090929B, Swift-BAT refined analysis
  86. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  87. GRB 090929A: Swift-XRT non-detection
  88. Konus-Wind observation of GRB 090929A
  89. Konus-Wind observation of GRB 090929B
  90. GRB 090927: Fermi GBM observation
  91. GRB 090929B: Swift-XRT refined analysis
  92. GRB 090929B: Skynet/DSO Observations
  93. GRB 090929B: Swift/UVOT Observations
  94. Konus-RF observation of GRB 090929A
  95. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  96. GRB 090929A BAT location of the Fermi GBM burst
  97. Correction: GRB 090929B: Enhanced Swift-XRT position
  98. GRB 090929: Enhanced Swift-XRT position
  99. GRB 090929B: Swift detection of a burst
  100. GRB090926A: Swift-XRT refined analysis

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