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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"

26309 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. Konus-Wind observations of GRB 091117A
  5. GRB 091112: Suzaku WAM observation of the prompt emission
  6. GRB 091102A: Suzaku WAM observation of the prompt emission
  7. GRB 091109B: Suzaku WAM observation of the prompt emission
  8. GRB091111: Swift XRT refined analysis
  9. Konus-Wind and Konus-RF observations of GRB 091031
  10. GRB 091112: Swift-BAT refined analysis
  11. GRB 091112: Fermi GBM observation
  12. GRB 091031: Fermi LAT detection of a faint burst
  13. GRB 091112: Swift detection of a possible burst
  14. GRB 091111: a faint long GRB detected with INTEGRAL
  15. GRB 091109B: Swift/UVOT Upper Limits
  16. GRB 091109B: VLT afterglow confirmation
  17. GRB 091109B: Swift-XRT Team refined analysis
  18. GRB 091109B: Swift-BAT refined analysis
  19. GRB 091109B: Enhanced Swift-XRT position
  20. GRB 091109B: Swift detection of a short burst
  21. GRB 091030: Fermi GBM detection
  22. GRB 091109: Swift-XRT refined analysis
  23. GRB 091109: BOOTES-3 observations
  24. GRB 091109: Faulkes Telescope South observations
  25. GRB 091109: Swift-BAT refined analysis
  26. GRB 091109: Enhanced Swift-XRT position
  27. GRB 091109: Swift detection of a burst with optical afterglow
  28. GRB 091104: Swift-BAT refined analysis
  29. GRB 091104: Swift XRT Refined Analysis
  30. GRB091026 : IRSF NIR upper limit
  31. GRB091102 : MOA optical upper limit
  32. GRB 091104: Enhanced Swift-XRT position
  33. GRB 091104: Swift detection of a burst
  34. Fermi LAT Upper Limits on GRB 091010
  35. GRB 091102 : Faulkes Telescope South Upper Limits
  36. GRB 091102A: Fermi GBM observation
  37. GRB 091102: Swift-XRT refined analysis
  38. GRB 091102: GROND Upper Limits
  39. GRB 091102: BOOTES-3 observations
  40. GRB 091102: Swift-BAT refined analysis
  41. GRB 091102: Swift/XRT localization
  42. GRB 091102: Swift detection of a burst
  43. GRB 091024: optical observations
  44. GRB 091031: Fermi GBM detection
  45. GRB 091024: Fermi LAT upper limits
  46. GRB 091029, SMARTS optical/IR afterglow observations
  47. GRB091029: Swift/UVOT observations
  48. GRB 091029: Swift XRT refined analysis
  49. GRB 091029: Swift-BAT refined analysis
  50. GRB 091029: Enhanced Swift-XRT position
  51. GRB091024 optical observations
  52. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  53. GRB 091029: Swift detection of a burst with an optical counterpart
  54. GRB 091020: Fermi GBM observation
  55. GRB 091026: Suzaku WAM observation of the prompt emission
  56. GRB 091024: Keck/LRIS Spectroscopy
  57. GRB 091024: YNAO-GMG observations
  58. GRB 091026: GROND Upper Limits
  59. GRB 091026: Swift-BAT refined analysis
  60. Radio afterglow detection from GRB 091020
  61. GRB 091024: Burst was outside the Swift-BAT FOV after T0(BAT)+460sec
  62. GRB 091026: Swift-XRT refined analysis
  63. GRB 091026: Enhanced Swift-XRT position
  64. Konus-Wind and Konus-RF observations of GRB 091024
  65. GRB 091026: Swift detection of a Gamma Ray Burst
  66. GRB091024 Swift/UVOT Upper Limits
  67. GRB 091020: Early TLS Multicolor detections, red afterglow
  68. GRB 091024: KAIT optical afterglow observations
  69. GRB091024: VRcIc Afterglow Observations
  70. GRB 091024: Swift-BAT refined analysis
  71. GRB 091024: Fermi GBM Observations
  72. GRB 091024: Swift-XRT team refined analysis
  73. Swift-BAT trigger 373691 is a galactic bulge transient
  74. GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
  75. GRB 091024: Swift detection of a burst
  76. GRB 091018: Skynet/PROMPT Continued Observations of Fading
  77. GRB 091020: Lick observations
  78. Konus-Wind observations of GRB 091010
  79. GRB 091020: Swift-XRT refined analysis
  80. GRB 091018: Swift XRT refined analysis
  81. GRB091020 Swift/UVOT observations
  82. GRB 091020: MASTER optical transient polarimetry
  83. GRB 091020, Swift-BAT refined analysis
  84. GRB 091020: Enhanced Swift-XRT position
  85. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  86. GRB 091020: Swift detection of a burst with an optical afterglow
  87. GRB 091018: miniTAO/ANIR Observations
  88. GRB 091018: Skynet/PROMPT Observations of Fading
  89. Konus-RF observation of GRB 091018
  90. GRB 091018: VLT/X-shooter spectra
  91. GRB091018: Swift/UVOT observations
  92. GRB 091018: Swift-BAT refined analysis
  93. GRB 091018: GROND observations
  94. GRB091018: Magellan Echellette Observations
  95. GRB 091018: Enhanced Swift-XRT position
  96. GRB 091018: Swift detection of a burst with optical afterglow
  97. GRB 091010: optical obsevation
  98. GRB 090726 R band observations
  99. GRB 090815: a faint long GRB localized by INTEGRAL
  100. GRB 091010: Swift-XRT refined analysis

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