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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"

11527 results found.

  1. GRB 230209A: Fermi GBM Final Real-time Localization
  2. GRB 221009A: Continued Swift Observations
  3. Fermi Gamma-ray Burst Monitor trigger 230208382/697540213 is not a GRB
  4. GRB 230208A: Fermi GBM Final Real-time Localization
  5. Fermi Gamma-ray Burst Monitor triggers 230206723/697396830 and 230206797/697403223 are not GRBs
  6. Fermi GRB 230207A: Global MASTER-Net observations report
  7. GRB 230207A: Fermi GBM Final Real-time Localization
  8. Fermi trigger No 697403223: Global MASTER-Net observations report
  9. Fermi trigger No 697396830: Global MASTER-Net observations report
  10. GRB 230204B: Fermi GBM detection
  11. Fermi Gamma-ray Burst Monitor triggers due to recent activity of RX J0440.9+4431 (LS V +44 17)
  12. GRB 230204B: Detection by GRBAlpha
  13. GRB 230204B: AGILE detection
  14. IceCube-230201A: BOOTES-4/MET Optical Upper Limits
  15. GRB 230204B: AstroSat CZTI detection
  16. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  17. Fermi trigger No 697208885: Global MASTER-Net observations report
  18. GRB 230201B: TURBO Optical Upper Limits
  19. Fermi Gamma-ray Burst Monitor trigger 230203275 / 697098930 is not a GRB
  20. Fermi trigger No 697098930: Global MASTER-Net observations report
  21. Fermi GRB 230201B: Global MASTER-Net observations report
  22. Fermi-LAT gamma-ray observations of IceCube-230201A
  23. GRB 230201B: Fermi GBM Final Real-time Localization
  24. GRB 230126A: Detection by VZLUSAT-2
  25. Fermi GRB 230201A: Global MASTER-Net observations report
  26. IceCube-230201A - IceCube observation of a high-energy neutrino candidate track-like event
  27. GRB 230201A: Fermi GBM Final Real-time Localization
  28. GRB 230129A: AstroSat CZTI detection
  29. GRB 230128A: AstroSat CZTI detection
  30. GRB 230130A: Fermi GBM Final Real-time Localization
  31. GRB 230129A: Fermi GBM Final Real-time Localization
  32. GRB 230128A: Fermi GBM Final Real-time Localization
  33. GRB 230126A: Fermi GBM Final Real-time Localization
  34. GRB 230124A: Fermi GBM Observation
  35. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  36. Fermi GRB 230124A: Global MASTER-Net observations report
  37. GRB 230124A: Fermi GBM Final Real-time Localization
  38. Fermi-LAT gamma-ray observations of IceCube-230122A
  39. IceCube-230122A - IceCube observation of a high-energy neutrino candidate track-like event
  40. GRB 230116B: Fermi GBM observation
  41. IPN triangulation of GRB 230116B (short)
  42. GRB 230119A: CALET Gamma-Ray Burst Monitor detection
  43. GRB 230119A: Fermi GBM Final Real-time Localization
  44. Fermi GRB 230118A: Global MASTER-Net observations report
  45. GRB 230118A: Fermi GBM Final Real-time Localization
  46. Fermi trigger No 695569700: Global MASTER-Net observations report
  47. Fermi GRB 230117A: Global MASTER-Net observations report
  48. GRB 230117A: Fermi GBM Final Real-time Localization
  49. GRB 230116B: Fermi GBM Final Real-time Localization
  50. GRB 230116A: Fermi GBM Final Real-time Localization
  51. GRB 230114A: Detection by VZLUSAT-2
  52. Fermi-LAT gamma-ray observations of IceCube-230112A
  53. GRB 230114A: Fermi GBM Final Real-time Localization
  54. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
  55. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
  56. GRB 230111A: Fermi GBM Observation
  57. IceCube-230112A - IceCube observation of a high-energy neutrino candidate track-like event
  58. Fermi GRB 230112A: Global MASTER-Net observations report
  59. GRB 230112A: Fermi GBM Final Real-time Localization
  60. GRB 230111A: Fermi GBM Final Real-time Localization
  61. Fermi trigger No 695057654: Global MASTER-Net observations report
  62. GRB 230102A: Fermi GBM Observation
  63. Fermi Gamma-ray Burst Monitor trigger 694043024/221229905 is not a GRB
  64. GRB 221231A: 3.6m DOT optical upper limit
  65. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  66. GRB 221231A: Fermi GBM Observation
  67. Fermi Gamma-ray Burst Monitor trigger 694259491/230101411 is not a GRB
  68. GRB 230102A: Detection by GRBAlpha
  69. Fermi Gamma-ray Burst Monitor trigger 694302022/230101903 is not a GRB
  70. GRB 230101A: AstroSat CZTI detection
  71. Fermi trigger No 694259491: Global MASTER-Net observations report
  72. GRB 230102A: AGILE/MCAL detection
  73. GRB 230102A: Fermi GBM Final Real-time Localization
  74. GRB 221231A: AKO Upper Limit
  75. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  76. Fermi trigger No 694232203: Global MASTER-Net observations report
  77. GRB 230101A: Fermi GBM Final Real-time Localization
  78. GRB 221231A: Fermi GBM Final Real-time Localization
  79. Fermi-LAT gamma-ray observations of IceCube-221229A
  80. GRB 221226A: Fermi GBM detection
  81. IPN triangulation of GRB 221226A
  82. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  83. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  84. GRB 221228A: Fermi GBM Final Real-time Localization
  85. GRB 221226A: AGILE detection
  86. GRB 221226B: Fermi GBM Observation
  87. GRB 221226B: VLT/X-shooter redshift and host galaxy
  88. GRB 221226B: Fermi GBM Final Real-time Localization
  89. Fermi GRB 221226A: Global MASTER-Net observations report
  90. GRB 221226A: Fermi GBM Final Real-time Localization
  91. Fermi-LAT gamma-ray observations of IceCube-221224A
  92. Fermi-LAT gamma-ray observations of IceCube-221223A
  93. Fermi GRB 221223A: Global MASTER-Net observations report
  94. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  95. GRB 221223A: Fermi GBM Final Real-time Localization
  96. IceCube-221223A - IceCube observation of a high-energy neutrino candidate track-like event
  97. GRB 221221A: AGILE detection
  98. Fermi GRB 221221A: Global MASTER-Net observations report
  99. GRB 221221A: Fermi GBM Final Real-time Localization
  100. GRB 221216A: Detection by VZLUSAT-2

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