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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

27332 results found.

  1. GRB 230204B: Swift/UVOT Upper Limits
  2. Fermi trigger No 697403223: Global MASTER-Net observations report
  3. Fermi trigger No 697396830: Global MASTER-Net observations report
  4. GRB 230205A: Swift/UVOT Upper Limits
  5. GRB 230204B: Fermi GBM detection
  6. Fermi Gamma-ray Burst Monitor triggers due to recent activity of RX J0440.9+4431 (LS V +44 17)
  7. GRB 230205A: LCOGT Optical Upper Limits
  8. GRB 230205A: SVOM/C-GFT optical upper limit
  9. GRB 230205A: OHP/T193 optical observations
  10. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  11. GRB 230204A: Swift-BAT refined analysis
  12. GRB 230205A: Swift-XRT refined Analysis
  13. GRB 230205A: BOOTES-5/JGT early optical upper limit
  14. GRB 230204B: Detection by GRBAlpha
  15. GRB 230205A: Swift detection of a burst
  16. GRB 230204B: GIT discovery of the likely optical afterglow
  17. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  18. GRB 230204A: Swift/UVOT Upper Limits
  19. GRB 230204A: Swift-XRT refined Analysis
  20. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  21. Fermi trigger No 697208885: Global MASTER-Net observations report
  22. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  23. GRB 230201B: TURBO Optical Upper Limits
  24. Fermi Gamma-ray Burst Monitor trigger 230203275 / 697098930 is not a GRB
  25. Fermi trigger No 697098930: Global MASTER-Net observations report
  26. GRB 221216A: Swift-BAT refined analysis
  27. IceCube Alert 230201.26: Global MASTER-Net observations report
  28. Fermi GRB 230201B: Global MASTER-Net observations report
  29. GRB 230201B: Fermi GBM Final Real-time Localization
  30. Fermi GRB 230201A: Global MASTER-Net observations report
  31. GRB 230201A: Fermi GBM Final Real-time Localization
  32. GRB 230130A: Fermi GBM Final Real-time Localization
  33. GRB 230129A: Fermi GBM Final Real-time Localization
  34. GRB 230128A: Fermi GBM Final Real-time Localization
  35. ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
  36. GRB 230126A: Fermi GBM Final Real-time Localization
  37. Trigger 1150965: Swift detection of LS V +44 17
  38. GRB 230124A: Fermi GBM Observation
  39. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  40. GRB 230114B: Detection by VZLUSAT-2
  41. GRB 230123A: LCOGT Optical Upper Limits
  42. Fermi GRB 230124A: Global MASTER-Net observations report
  43. GRB 230124A: Fermi GBM Final Real-time Localization
  44. GRB 230123A: Swift-BAT refined analysis
  45. GRB 230122A: Swift/BAT-GUANO detection
  46. GRB 230123A: Swift/UVOT Upper Limits
  47. GRB 230123A: Swift-XRT refined Analysis
  48. GRB 230123A: Zadko observatory - Gingin optical observations
  49. GRB 230123A: Swift detection of a burst
  50. IceCube Alert 230122.16: Global MASTER-Net observations report
  51. GRB 230116B: Fermi GBM observation
  52. Trigger 1150107: Swift detection of LS V +44 17
  53. IPN triangulation of GRB 230116B (short)
  54. GRB 230119A: CALET Gamma-Ray Burst Monitor detection
  55. GRB 230119A: Fermi GBM Final Real-time Localization
  56. Fermi GRB 230118A: Global MASTER-Net observations report
  57. GRB 230118A: Fermi GBM Final Real-time Localization
  58. GRB 230116D: Swift-BAT refined analysis
  59. GRB 230116C: Swift-BAT refined analysis
  60. GRB 230116D: LCOGT Optical Upper Limit
  61. Fermi trigger No 695569700: Global MASTER-Net observations report
  62. GRB 230116D: Swift-XRT refined Analysis
  63. Fermi GRB 230117A: Global MASTER-Net observations report
  64. GRB 230117A: Fermi GBM Final Real-time Localization
  65. GRB 230116D: GIT optical follow-up
  66. GRB 230116D: Nanshan/NEXT optical afterglow detection
  67. GRB 230116D: Swift detection of a burst
  68. Swift GRB230116.88: Global MASTER-Net observations report
  69. GRB 230116C: Swift detection of a burst
  70. GRB 230116B: Fermi GBM Final Real-time Localization
  71. GRB 230116A: Fermi GBM Final Real-time Localization
  72. GRB 230114A: Fermi GBM Final Real-time Localization
  73. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  74. GRB 230111A: Fermi GBM Observation
  75. Fermi GRB 230112A: Global MASTER-Net observations report
  76. IceCube Alert 230112.28: Global MASTER-Net observations report
  77. GRB 230112A: Fermi GBM Final Real-time Localization
  78. GRB 230111A: Fermi GBM Final Real-time Localization
  79. Fermi trigger No 695057654: Global MASTER-Net observations report
  80. GRB 230102A: Fermi GBM Observation
  81. Fermi Gamma-ray Burst Monitor trigger 694043024/221229905 is not a GRB
  82. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  83. GRB 221231A: Fermi GBM Observation
  84. GRB 221230A: CALET Gamma-Ray Burst Monitor detection
  85. Fermi Gamma-ray Burst Monitor trigger 694259491/230101411 is not a GRB
  86. Fermi Gamma-ray Burst Monitor trigger 694302022/230101903 is not a GRB
  87. Fermi trigger No 694259491: Global MASTER-Net observations report
  88. GRB 230102A: Fermi GBM Final Real-time Localization
  89. GRB 221231A: AKO Upper Limit
  90. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  91. Fermi trigger No 694232203: Global MASTER-Net observations report
  92. GRB 230101A: Fermi GBM Final Real-time Localization
  93. GRB 221231A: Fermi GBM Final Real-time Localization
  94. GRB 221226A: Fermi GBM detection
  95. IPN triangulation of GRB 221226A
  96. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  97. GRB 221226B: LCOGT Optical Upper Limits
  98. GRB 221228A: Fermi GBM Final Real-time Localization
  99. GRB 221226B Swift-BAT refined analysis
  100. GRB 221226B: Swift-UVOT Detection

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