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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"

27410 results found.

  1. GRB 091020: Swift-XRT refined analysis
  2. GRB 091018: Swift XRT refined analysis
  3. GRB091020 Swift/UVOT observations
  4. GRB 091020, Swift-BAT refined analysis
  5. GRB 091020: Enhanced Swift-XRT position
  6. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  7. GRB 091020: Swift detection of a burst with an optical afterglow
  8. GRB 091018: Skynet/PROMPT Observations of Fading
  9. Konus-RF observation of GRB 091018
  10. GRB 091018 : Faulkes Telescope South Observations
  11. GRB091018: Swift/UVOT observations
  12. GRB 091018: Swift-BAT refined analysis
  13. GRB 091018: Enhanced Swift-XRT position
  14. GRB 091018: ROTSE-III Detection of Optical Counterpart
  15. GRB 091015: Skynet/PROMPT Observations
  16. GRB 091018: Swift detection of a burst with optical afterglow
  17. GRB 091010: optical obsevation
  18. GRB 090726 R band observations
  19. GRB 091010: optical afterglow candidate rejection
  20. GRB 091010: Swift-XRT refined analysis
  21. GRB 091010: Suzaku WAM observation of the prompt emission
  22. GRB 091010: AGILE-MCAL measurement and GRID upper limit
  23. Radio observation of GRB090927 with ATCA
  24. Radio observation of GRB090926a with ATCA
  25. Radio observation of GRB080916c with ATCA
  26. GRB 091010: Fermi GBM observation
  27. GRB 091010: Faulkes Telescope North observations
  28. GRB 090531A: Skynet/PROMPT Observations
  29. GRB 090530A: Skynet/DSO Detections
  30. GRB 091010: Enhanced XRT position
  31. GRB 091010 optical upper limits
  32. Detection of a short GRB 090929A by RT-2 Experiment
  33. GRB 091010: GROND afterglow candidate
  34. GRB 091010: Swift/UVOT Upper Limits
  35. GRB 091010: Swift-XRT position
  36. GRB 090910: SuperAGILE Localization of a Long GRB
  37. GRB 090926A: Skynet/PROMPT Observations of Day 6 - 11 Fading
  38. GRB 090518: Skynet/PROMPT Observations
  39. Short-Duration GRB 090621: Skynet/Dolomiti Observations
  40. GRB 090904A: afterglow confirmation
  41. GRB 090812: Skynet/PROMPT and GORT Observations
  42. GRB 091003A: Suzaku WAM observation of the prompt emission
  43. GRB 090926B: Skynet/PROMPT Observations
  44. GRB 091003: WHT ACAM observations
  45. GRB 090929B: Suzaku WAM observation of the prompt emission
  46. GRB 090929A: Suzaku WAM observation of the prompt emission
  47. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  48. GRB 091003: Skynet/DSO Observations
  49. GRB 091003: UVOT-enhanced XRT position
  50. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  51. GRB 091003A: Fermi LAT detection
  52. GRB 090926A: Skynet/PROMPT Observations of Day 4 - 6 Fading Rate
  53. GRB 091003A: Fermi GBM detection
  54. GRB 090926A: Skynet/PROMPT Observations of Post-Peak Fading
  55. GRB 090929A, Swift-BAT refined analysis
  56. GRB 090929B, Swift-BAT refined analysis
  57. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  58. GRB 090929A: Swift-XRT non-detection
  59. Konus-Wind observation of GRB 090929B
  60. GRB 090929B: Swift-XRT refined analysis
  61. GRB 090929B: Gemini-N upper limits
  62. GRB 090929B: Skynet/DSO Observations
  63. GRB 090929B: Swift/UVOT Observations
  64. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  65. GRB 090929A BAT location of the Fermi GBM burst
  66. Correction: GRB 090929B: Enhanced Swift-XRT position
  67. GRB 090929: Enhanced Swift-XRT position
  68. GRB 090929B: Swift detection of a burst
  69. GRB 090929A: Fermi GBM detection
  70. GRB090926A: Swift-XRT refined analysis
  71. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  72. GRB 090927: Zadko Telescope observations
  73. GRB 090927, Swift-BAT refined analysis of the possibly short burst
  74. Swift/UVOT observations of GRB 090927
  75. GRB 090926A: Skynet/PROMPT Continued Observations
  76. GRB 090927: Swift XRT refined analysis
  77. GRB 090926A: Suzaku WAM observation of the prompt emission
  78. GRB 090927: Enhanced Swift-XRT position
  79. GRB090926B: Swift/UVOT Upper Limits
  80. GRB090926A: Swift/UVOT observations
  81. GRB 090927: Swift/UVOT detection of an optical afterglow
  82. GRB 090927: Swift detection of a short burst
  83. GRB 090926B: optical object in error circle
  84. GRB 090926B: MAXI GSC detection
  85. GRB 090926B: NOT optical observation
  86. GRB 090926B: Swift XRT refined analysis
  87. GRB 090926B: Swift-BAT refined analysis
  88. GRB 090926A: Swift/UVOT detection of an optical afterglow
  89. GRB090926A: UVOT-enhanced XRT position
  90. GRB 090926B: Swift detection of a burst
  91. GRB 090926: Fermi LAT detection
  92. GRB 090926: Fermi GBM detection
  93. GRB 090925: Fermi GBM detection
  94. GRB090922A: correction to Fermi location
  95. GRB 090922A: Fermi GBM detection
  96. GRB 090715B: Skynet/PROMPT Detections
  97. GRB 090726: Skynet/GORT Observations
  98. GRB 090916: Swift-XRT upper limit
  99. GRB 090807: Skynet/DSO Observations
  100. GRB 090915: GROND upper limits

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