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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"

25850 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: BOOTES-3 observations
  5. GRB 091102: Swift-BAT refined analysis
  6. GRB 091102: Swift/XRT localization
  7. GRB 091024: optical observations
  8. GRB 091031: Fermi GBM detection
  9. GRB 091024: Fermi LAT upper limits
  10. GRB 091018, SMARTS optical/IR afterglow observations
  11. GRB091029: Swift/UVOT observations
  12. GRB 091029: Swift XRT refined analysis
  13. GRB 091029: Swift-BAT refined analysis
  14. GRB 091029: Enhanced Swift-XRT position
  15. GRB091024 optical observations
  16. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  17. GRB 091029: Swift detection of a burst with an optical counterpart
  18. GRB 091020: Fermi GBM observation
  19. GRB 091026: Suzaku WAM observation of the prompt emission
  20. GRB 091026: GROND Upper Limits
  21. Radio afterglow detection from GRB 091020
  22. GRB 091026: Swift/UVOT Upper Limits
  23. GRB 091026: Swift-XRT refined analysis
  24. GRB 091026: Enhanced Swift-XRT position
  25. Konus-Wind and Konus-RF observations of GRB 091024
  26. GRB 091026: Updated Swift-XRT position
  27. GRB 091026: Swift detection of a Gamma Ray Burst
  28. GRB091024 Swift/UVOT Upper Limits
  29. GRB 091024: TLS Upper Limit
  30. GRB 091020: Early TLS Multicolor detections, red afterglow
  31. GRB 091024: Super-LOTIS early observations
  32. GRB 091024: Swift-BAT refined analysis
  33. GRB 091024: Fermi GBM Observations
  34. GRB 091024: Swift-XRT team refined analysis
  35. GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
  36. GRB 091024: GRAS004 optical observations
  37. GRB 091024: Faulkes Telescope North Afterglow Candidate
  38. Konus-Wind observations of GRB 091010
  39. GRB 091020: Swift-XRT refined analysis
  40. GRB 091018: Swift XRT refined analysis
  41. GRB091020 Swift/UVOT observations
  42. GRB 091020, Swift-BAT refined analysis
  43. GRB 091020: Enhanced Swift-XRT position
  44. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  45. GRB 091020: Swift detection of a burst with an optical afterglow
  46. GRB 091018: miniTAO/ANIR Observations
  47. GRB 091018: Skynet/PROMPT Observations of Fading
  48. Konus-RF observation of GRB 091018
  49. GRB 091018 : Faulkes Telescope South Observations
  50. GRB091018: Swift/UVOT observations
  51. GRB 091018: Enhanced Swift-XRT position
  52. GRB 091018: Swift detection of a burst with optical afterglow
  53. GRB 091003: Gemini-N redshift of possible host galaxy
  54. GRB 091010: optical obsevation
  55. GRB 091010: optical afterglow candidate rejection
  56. GRB 091010: Swift-XRT refined analysis
  57. GRB 091010: Suzaku WAM observation of the prompt emission
  58. GRB 091010: AGILE-MCAL measurement and GRID upper limit
  59. Radio observation of GRB090927 with ATCA
  60. Radio observation of GRB090926a with ATCA
  61. Radio observation of GRB080916c with ATCA
  62. GRB 091010: Fermi GBM observation
  63. GRB 091010: Faulkes Telescope North observations
  64. GRB 091010: RXTE detection
  65. Konus-Wind observations of GRB 091010
  66. GRB 091010: Enhanced XRT position
  67. GRB 091010 optical upper limits
  68. Detection of a short GRB 090929A by RT-2 Experiment
  69. RT-2 observation of the bright GRB 090926A
  70. GRB 091010: GROND afterglow candidate
  71. GRB 091010: Swift/UVOT Upper Limits
  72. GRB 090910: SuperAGILE Localization of a Long GRB
  73. GRB 090518: Skynet/PROMPT Observations
  74. GRB 090904A: afterglow confirmation
  75. GRB 090812: Skynet/PROMPT and GORT Observations
  76. GRB 091003A: Suzaku WAM observation of the prompt emission
  77. GRB 090926B: Skynet/PROMPT Observations
  78. GRB 091003: WHT ACAM observations
  79. Konus-Wind observation of GRB 091003A
  80. GRB 090929B: Suzaku WAM observation of the prompt emission
  81. GRB 090929A: Suzaku WAM observation of the prompt emission
  82. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  83. GRB 091003: UVOT-enhanced XRT position
  84. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  85. GRB 091003: Swift XRT analysis
  86. GRB 091003A: Fermi LAT detection
  87. GRB 091003A: Fermi GBM detection
  88. GRB 090929A, Swift-BAT refined analysis
  89. GRB 090929B, Swift-BAT refined analysis
  90. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  91. GRB 090929A: Swift-XRT non-detection
  92. Konus-Wind observation of GRB 090929A
  93. GRB 090927: Fermi GBM observation
  94. GRB 090929B: Swift-XRT refined analysis
  95. GRB 090926A: Fermi LAT and GBM refined analysis
  96. GRB 090929B: Gemini-N upper limits
  97. GRB 090929B: Swift/UVOT Observations
  98. Konus-RF observation of GRB 090929A
  99. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  100. GRB 090929A BAT location of the Fermi GBM burst

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