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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"

25571 results found.

  1. GRB 091102: BOOTES-3 observations
  2. GRB 091102: Swift-BAT refined analysis
  3. GRB 091102: Swift/XRT localization
  4. GRB 091102: Swift detection of a burst
  5. GRB 091024: optical observations
  6. GRB 091031: Fermi GBM detection
  7. GRB 091024: Fermi LAT upper limits
  8. GRB 091029, SMARTS optical/IR afterglow observations
  9. GRB091029: Swift/UVOT observations
  10. GRB 091029: Swift XRT refined analysis
  11. GRB 091029: Swift-BAT refined analysis
  12. GRB 091029: Enhanced Swift-XRT position
  13. GRB091024 optical observations
  14. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  15. GRB 091029: Swift detection of a burst with an optical counterpart
  16. GRB 091020: Fermi GBM observation
  17. GRB 091026: Suzaku WAM observation of the prompt emission
  18. GRB 091024: Keck/LRIS Spectroscopy
  19. GRB 091024: YNAO-GMG observations
  20. GRB 091026: GROND Upper Limits
  21. GRB 091026: Swift-BAT refined analysis
  22. Radio afterglow detection from GRB 091020
  23. GRB 091024: Burst was outside the Swift-BAT FOV after T0(BAT)+460sec
  24. GRB 091026: Swift-XRT refined analysis
  25. GRB 091026: Enhanced Swift-XRT position
  26. Konus-Wind and Konus-RF observations of GRB 091024
  27. GRB 091026: Swift detection of a Gamma Ray Burst
  28. GRB091024 Swift/UVOT Upper Limits
  29. GRB 091020: Early TLS Multicolor detections, red afterglow
  30. GRB 091024: KAIT optical afterglow observations
  31. GRB091024: VRcIc Afterglow Observations
  32. GRB 091024: Swift-BAT refined analysis
  33. GRB 091024: Fermi GBM Observations
  34. GRB 091024: Swift-XRT team refined analysis
  35. Swift-BAT trigger 373691 is a galactic bulge transient
  36. GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
  37. GRB 091024: Swift detection of a burst
  38. GRB 091018: Skynet/PROMPT Continued Observations of Fading
  39. GRB 091020: Lick observations
  40. Konus-Wind observations of GRB 091010
  41. GRB 091020: Swift-XRT refined analysis
  42. GRB 091018: Swift XRT refined analysis
  43. GRB091020 Swift/UVOT observations
  44. GRB 091020: MASTER optical transient polarimetry
  45. GRB 091020, Swift-BAT refined analysis
  46. GRB 091020: Enhanced Swift-XRT position
  47. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  48. GRB 091020: Swift detection of a burst with an optical afterglow
  49. GRB 091018: miniTAO/ANIR Observations
  50. GRB 091018: Skynet/PROMPT Observations of Fading
  51. Konus-RF observation of GRB 091018
  52. GRB 091018: VLT/X-shooter spectra
  53. GRB091018: Swift/UVOT observations
  54. GRB 091018: Swift-BAT refined analysis
  55. GRB 091018: GROND observations
  56. GRB091018: Magellan Echellette Observations
  57. GRB 091018: Enhanced Swift-XRT position
  58. GRB 091018: Swift detection of a burst with optical afterglow
  59. GRB 091010: optical obsevation
  60. GRB 090726 R band observations
  61. GRB 090815: a faint long GRB localized by INTEGRAL
  62. GRB 091010: Swift-XRT refined analysis
  63. GRB 091010: Suzaku WAM observation of the prompt emission
  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: Fermi GBM observation
  69. Konus-Wind observations of GRB 091010
  70. GRB 091010: Enhanced XRT position
  71. Detection of a short GRB 090929A by RT-2 Experiment
  72. RT-2 observation of the bright GRB 090926A
  73. GRB 091010: Swift-XRT position
  74. GRB 091003A: Suzaku WAM observation of the prompt emission
  75. Konus-Wind observation of GRB 091003A
  76. GRB 090929B: Suzaku WAM observation of the prompt emission
  77. GRB 090929A: Suzaku WAM observation of the prompt emission
  78. GRB 091003: Swift-XRT confirmation of fading afterglow
  79. GRB 091003: UVOT-enhanced XRT position
  80. GRB 091003A: Fermi LAT detection
  81. GRB 091003A: Fermi GBM detection
  82. GRB 090929A, Swift-BAT refined analysis
  83. GRB 090929B, Swift-BAT refined analysis
  84. GRB 090929A: Swift-XRT non-detection
  85. Konus-Wind observation of GRB 090929A
  86. Konus-Wind observation of GRB 090929B
  87. GRB 090927: Fermi GBM observation
  88. GRB 090929B: Swift-XRT refined analysis
  89. GRB 090926A: Fermi LAT and GBM refined analysis
  90. GRB 090929B: Swift/UVOT Observations
  91. Konus-RF observation of GRB 090929A
  92. Correction: GRB 090929B: Enhanced Swift-XRT position
  93. GRB 090929: Enhanced Swift-XRT position
  94. GRB 090929B: Swift detection of a burst
  95. GRB 090929A: Fermi GBM detection
  96. GRB090926A: Swift-XRT refined analysis
  97. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  98. Konus-Wind and Konus-RF observations of GRB 090926A
  99. GRB 090926B: Fermi GBM detection
  100. GRB 090927, Swift-BAT refined analysis of the possibly short burst

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