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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"

12096 results found.

  1. GRB 220426C: Swift/BAT-GUANO detection outside the coded FOV (short)
  2. Fermi GRB 220426A: Global MASTER-Net observations report
  3. GRB 220426A: Swift/BAT-GUANO detection outside the coded FOV
  4. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  5. Fermi GRB 220426B: Global MASTER-Net observations report
  6. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  7. IceCube Alert 220425.11: Global MASTER-Net observations report
  8. Fermi trigger No 672492774: Global MASTER-Net observations report
  9. GRB 220423A: Swift/BAT-GUANO detection outside the coded FOV
  10. IceCube Alert 220424.05: Global MASTER-Net observations report
  11. GRB 220423A: AGILE detection
  12. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  13. GRB 220421A: Swift/BAT-GUANO detection outside the coded FOV
  14. Fermi GBM trigger 672128054/220420260 is not a GRB
  15. IceCube-220421A - IceCube observation of a high-energy neutrino candidate track-like event
  16. Fermi trigger No 672093919: Global MASTER-Net observations report
  17. GRB 220420A: Swift/BAT-GUANO detection outside the coded FOV
  18. IPN triangulation of GRB 220411A
  19. GRB 220418B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  20. GRB 220417A: Swift/BAT-GUANO detection outside the coded FOV
  21. Fermi GRB 220417A: Global MASTER-Net observations report
  22. Konus-Wind detection of GRB 220412B
  23. GRB 220412B: Fermi GBM observation
  24. Konus-Wind detection of GRB 220403C
  25. Konus-Wind detection of GRB 220408B
  26. GRB 220412A: Swift-BAT refined analysis
  27. GRB 220408B: Fermi-LAT detection
  28. GRB 220412A: Swift-XRT refined Analysis
  29. GRB 220412A: Enhanced Swift-XRT position
  30. GRB 220412A: Swift/UVOT Upper Limits
  31. GRB 220408A: GRANDMA observations
  32. GRB 220412A: Swift detection of a burst
  33. Swift GRB220412.28: Global MASTER-Net observations report
  34. GRB 220411A: AstroSat CZTI detection
  35. IPN triangulation of GRB 220408B
  36. IPN triangulation of GRB 220403C
  37. Fermi GRB 220411A: Global MASTER-Net observations report
  38. GRB 220411A: BALROG localization (Fermi Trigger 671354405/ GRB 220411306)
  39. GRB 220411A: Fermi GBM Final Real-time Localization
  40. GRB 220408A: LOAO, DOAO, and, SAO optical upper limit
  41. GRB 220408B: AstroSat CZTI detection
  42. GRB 220408A: Swift-XRT refined Analysis
  43. Fermi GRB 220408B: Global MASTER-Net observations report
  44. GRB 220408A: Fermi GBM observation
  45. Chandra upper limit at the location of GRB 220408A
  46. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  47. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
  48. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  49. GRB 220403B: Mondy optical upper limit
  50. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  51. GRB 220403B: 1.5m OSN optical observation
  52. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  53. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  54. IceCube Alert 220405.21: Global MASTER-Net observations report
  55. GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  56. GRB 220403B: Fermi GBM detection
  57. GRB 220404A: Swift detection of a burst
  58. GRB 220403C (or A): Swift/BAT-GUANO detection outside the coded FOV
  59. GRB 220403B: Swift detection of a burst with an optical counterpart
  60. GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
  61. Swift GRB220402.16: Global MASTER-Net observations report
  62. Fermi GRB 220401B: Global MASTER-Net observations report
  63. Fermi GRB 220330A: Global MASTER-Net observations report
  64. Konus-Wind observation of GRB 220320A
  65. GRB 220325A: 1.3m DFOT Optical upper limit
  66. GRB 220324A: AstroSat CZTI detection
  67. GRB 220323A: AstroSat CZTI detection
  68. GRB 220316A: AstroSat CZTI detection
  69. GRB 220320A: AstroSat CZTI detection
  70. GRB 220319A: LCO Optical Upper Limit
  71. GRB 220319A: Swift-XRT refined Analysis
  72. GRB 220319A: MASTER Global Robotic Net optical observations
  73. GRB 220319A: Swift detection of a burst
  74. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  75. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
  76. IceCube-220317A: MASTER Global Robotic Net optical observations
  77. GRB 220310C: Swift-XRT observations
  78. Konus-Wind detection of GRB 220310A
  79. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  80. GRB 220311A: A long GRB detected by INTEGRAL
  81. Integral GRB220311.69: Global MASTER-Net observations report
  82. GRB 220308A: AGILE detection
  83. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  84. GRB 220310A: MAXI/GSC detection
  85. Konus-Wind detection of GRB 220308A
  86. Fermi GRB 220309A: Global MASTER-Net observations report
  87. GRB 220308A: Swift/BAT-GUANO detection outside the coded FOV
  88. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  89. IPN triangulation of GRB 220305B
  90. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  91. GRB 220306B: BOOTES-1 optical upper limit
  92. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  93. GRB 220306A: Fermi GBM Final Real-time Localization
  94. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  95. IceCube Alert 220304.74: Global MASTER-Net observations report
  96. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  97. Fermi GRB 220304A: Global MASTER-Net observations report
  98. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  99. GRB 220302A: Swift detection of a burst
  100. GRB 220228A: Fermi-LAT detection

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