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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

18487 results found.

  1. GRB 091117: Evidence for Variability of XRT Source #1
  2. GRB091117: Gemini South Observations
  3. GRB 091117: Swift XRT refined analysis
  4. GRB091111: Swift XRT refined analysis
  5. GRB 091031: Fermi LAT detection of a faint burst
  6. GRB 091111: BOOTES-3 contemporaneous imaging
  7. GRB 091111: BOOTES-3 observations
  8. GRB 091109A: GROND and VLT observations
  9. GRB 091109B: Swift/UVOT Upper Limits
  10. GRB 091109B: Enhanced Swift-XRT position
  11. GRB 091109B: Optical limits from Watcher
  12. GRB 091109B: ROTSE-III Optical Limits
  13. GRB 091109B: Swift detection of a short burst
  14. GRB 091109: BOOTES-3 observations
  15. GRB 091109: Swift/UVOT observations
  16. GRB 091109: Faulkes Telescope South observations
  17. GRB 091109: Enhanced Swift-XRT position
  18. GRB091109: REM detection of the NIR afterglow
  19. GRB 091109: Swift detection of a burst with optical afterglow
  20. GRB 091029: Observations from Stardome Observatory
  21. GRB 091104: Swift/UVOT Upper Limits
  22. GRB 091104: Enhanced Swift-XRT position
  23. GRB 091104: Swift detection of a burst
  24. GRB 091102: LABOCA/APEX submm observations
  25. Fermi LAT Upper Limits on GRB 091010
  26. GRB 091102 : Faulkes Telescope South Upper Limits
  27. GRB 091102: Swift/UVOT Upper Limits
  28. GRB 091102: GROND Upper Limits
  29. GRB 091102: BOOTES-3 observations
  30. GRB 091102: Swift/XRT localization
  31. GRB 091024: optical observations
  32. GRB 091024: Fermi LAT upper limits
  33. GRB 091018, SMARTS optical/IR afterglow observations
  34. GRB091029: Swift/UVOT observations
  35. GRB 091029: Enhanced Swift-XRT position
  36. GRB091024 optical observations
  37. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  38. GRB 091029: Swift detection of a burst with an optical counterpart
  39. GRB 091026: Suzaku WAM observation of the prompt emission
  40. GRB 091026: GROND Upper Limits
  41. Radio afterglow detection from GRB 091020
  42. GRB 091026: Swift/UVOT Upper Limits
  43. GRB 091026: Enhanced Swift-XRT position
  44. GRB 091026: Swift detection of a Gamma Ray Burst
  45. GRB091024 Swift/UVOT Upper Limits
  46. GRB 091024: Super-LOTIS early observations
  47. GRB091024: VRcIc Afterglow Observations
  48. GRB 091024: Fermi GBM Observations
  49. GRB 091024: Swift-XRT team refined analysis
  50. GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
  51. GRB 091024: GRAS004 optical observations
  52. GRB091020 Swift/UVOT observations
  53. GRB 091020: Enhanced Swift-XRT position
  54. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  55. GRB 091020: Swift detection of a burst with an optical afterglow
  56. GRB 091018: Skynet/PROMPT Observations of Fading
  57. GRB 091018 : Faulkes Telescope South Observations
  58. GRB091018: Swift/UVOT observations
  59. GRB 091018: Enhanced Swift-XRT position
  60. GRB 091018: Swift detection of a burst with optical afterglow
  61. GRB 091010: optical obsevation
  62. GRB 091010: Swift-XRT refined analysis
  63. GRB 091010: AGILE-MCAL measurement and GRID upper limit
  64. Radio observation of GRB090927 with ATCA
  65. Radio observation of GRB090926a with ATCA
  66. Radio observation of GRB080916c with ATCA
  67. GRB 091010: Enhanced XRT position
  68. GRB 091010 optical upper limits
  69. GRB 091010: GROND afterglow candidate
  70. GRB 091010: Swift/UVOT Upper Limits
  71. GRB 090904A: afterglow confirmation
  72. GRB 090812: Skynet/PROMPT and GORT Observations
  73. GRB 091003: WHT ACAM observations
  74. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  75. GRB 091003: UVOT-enhanced XRT position
  76. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  77. GRB 091003A: Fermi LAT detection
  78. GRB 090929B, Swift-BAT refined analysis
  79. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  80. GRB 090929A: Swift-XRT non-detection
  81. GRB 090929B: Gemini-N upper limits
  82. GRB 090929B: Swift/UVOT Observations
  83. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  84. Correction: GRB 090929B: Enhanced Swift-XRT position
  85. GRB 090929: Enhanced Swift-XRT position
  86. GRB 090929B: Swift detection of a burst
  87. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  88. GRB 090927: Zadko Telescope observations
  89. Swift/UVOT observations of GRB 090927
  90. GRB 090927: Swift XRT refined analysis
  91. GRB 090927: Enhanced Swift-XRT position
  92. GRB090926B: Swift/UVOT Upper Limits
  93. GRB090926A: Swift/UVOT observations
  94. GRB 090926B: optical object in error circle
  95. GRB 090926B: NOT optical observation
  96. GRB 090926B: Swift XRT refined analysis
  97. GRB 090926A: Swift/UVOT detection of an optical afterglow
  98. GRB090926A: UVOT-enhanced XRT position
  99. GRB 090926B: Swift detection of a burst
  100. GRB 090926: Fermi LAT detection

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