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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"

18488 results found.

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

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