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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"

27769 results found.

  1. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  2. IceCube-230112A - IceCube observation of a high-energy neutrino candidate track-like event
  3. GRB 230112A: Fermi GBM Final Real-time Localization
  4. GRB 230111A: MAXI/GSC detection
  5. GRB 230111A: Fermi GBM Final Real-time Localization
  6. GRB 230106: AstroSat LAXPC detection
  7. GRB 230102A: Fermi GBM Observation
  8. GRB 221231A: 3.6m DOT optical upper limit
  9. GRB 230104A: AGILE/MCAL detection of a burst
  10. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  11. GRB 221231A: Fermi GBM Observation
  12. GRB 221230A: CALET Gamma-Ray Burst Monitor detection
  13. GRB 230102A: Detection by GRBAlpha
  14. GRB 230101A: AstroSat CZTI detection
  15. GRB 221231A: Swift-XRT afterglow detection
  16. GRB 230102A: AGILE/MCAL detection
  17. GRB 230102A: Fermi GBM Final Real-time Localization
  18. GRB 221231A: AKO Upper Limit
  19. GRB 221231A: Swift-XRT observations
  20. GRB 221231A: Swift ToO observations
  21. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  22. GRB 230101A: Fermi GBM Final Real-time Localization
  23. GRB 221231A: Fermi GBM Final Real-time Localization
  24. GRB 221226A: Fermi GBM detection
  25. IPN triangulation of GRB 221226A
  26. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  27. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  28. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  29. GRB 221228A: Fermi GBM Final Real-time Localization
  30. GRB 221226B Swift-BAT refined analysis
  31. GRB 221226B: Swift-UVOT Detection
  32. GRB 221226A: AGILE detection
  33. GRB 221226B: Fermi GBM Observation
  34. GRB 221226B: Swift-XRT refined Analysis
  35. GRB 221226B: VLT/X-shooter redshift and host galaxy
  36. GRB 221226B: Enhanced Swift-XRT position
  37. GRB 221226B: Swift detection of a burst
  38. GRB 221226B: Fermi GBM Final Real-time Localization
  39. Swift GRB221226.95: Global MASTER-Net observations report
  40. GRB 221226A: Fermi GBM Final Real-time Localization
  41. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  42. GRB 221223A: Fermi GBM Final Real-time Localization
  43. IceCube-221223A - IceCube observation of a high-energy neutrino candidate track-like event
  44. GRB 221221A: AGILE detection
  45. GRB 221221A: Fermi GBM Final Real-time Localization
  46. GRB 221218A: 3.6m DOT optical upper limit
  47. GRB 221216A: Detection by VZLUSAT-2
  48. GRB 221218A: BOOTES-4/MET and OSN optical upper limits
  49. GRB 221215A: Fermi GBM Detection
  50. GRB 221216A: Swift/UVOT Upper Limits
  51. GRB 221216A: Fermi GBM observation
  52. GRB 221216A: Swift-XRT refined Analysis
  53. GRB 221216A: AKO Upper Limit
  54. GRB 221215A: Swift-XRT observations
  55. GRB 221216A: Enhanced Swift-XRT position
  56. Swift GRB 221216A: Global MASTER-Net observations report
  57. GRB 221216A: Zadko observatory - Gingin optical observations
  58. GRB 221216A: Nanshan/NEXT optical upper limits
  59. GRB 221216A: Swift detection of a burst
  60. GRB 221216A: Fermi GBM Final Real-time Localization
  61. IceCube-221216A - IceCube observation of a high-energy neutrino candidate track-like event
  62. GRB 221215A: Swift ToO observations
  63. GRB 221215A: Swift/BAT-GUANO arcminute localization
  64. Konus-Wind detection of GRB 221209A
  65. IPN triangulation of GRB 221209A (long)
  66. GRB 221215B: Fermi GBM Final Real-time Localization
  67. Swift GRB221215.15: Global MASTER-Net observations report
  68. GRB 221215A: Fermi GBM Final Real-time Localization
  69. Swift Trigger 1144538 is not a GRB
  70. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 December 13
  71. GRB 221209A: CALET Gamma-Ray Burst Monitor detection
  72. GRB 221212A: Fermi GBM Final Real-time Localization
  73. GRB 221208A: AstroSat CZTI detection
  74. GRB 221211A: Fermi GBM Final Real-time Localization
  75. IceCube-221210A - IceCube observation of a high-energy neutrino candidate track-like event
  76. GRB 221009A: MuSCAT3 observations
  77. GRB 221209A: AstroSat CZTI detection
  78. GRB 221210A: Fermi GBM Final Real-time Localization
  79. GRB 221209B: Fermi GBM Final Real-time Localization
  80. GRB 221203C: AstroSat CZTI detection
  81. GRB 221209A: Fermi GBM Final Real-time Localization
  82. GRB 221206B: Fermi GBM observation
  83. GRB 221206B: Swift-XRT observations
  84. GRB 221206B: Detection by GRBAlpha
  85. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  86. GRB 221206B: Swift ToO observations
  87. Swift/BAT trigger #1143281 is not a GRB
  88. GRB 221206C: Fermi GBM Final Real-time Localization
  89. GRB 221206B: Fermi GBM Final Real-time Localization
  90. GRB 221206A: Fermi GBM Final Real-time Localization
  91. GRB 221205A: Fermi GBM Final Real-time Localization
  92. Swift GRB221204.45 AKO Upper Limit
  93. GRB 221202B: Detection by VZLUSAT-2
  94. Swift GRB221204.45: Global MASTER-Net observations report
  95. GRB 221203B: Fermi GBM Final Real-time Localization
  96. GRB 221202A: Swift/UVOT Detection
  97. GRB 221202A: Swift-BAT refined analysis
  98. GRB 221202A: VLT/FORS2 Afterglow Discovery
  99. GRB 221201A: Swift-BAT refined analysis
  100. GRB 221203A: Fermi GBM Final Real-time Localization

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