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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"

10781 results found.

  1. Fermi trigger No 672093919: Global MASTER-Net observations report
  2. GRB 220420A: Swift/BAT-GUANO detection outside the coded FOV
  3. IPN triangulation of GRB 220411A
  4. GRB 220418B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  5. GRB 220417A: Swift/BAT-GUANO detection outside the coded FOV
  6. Fermi GRB 220417A: Global MASTER-Net observations report
  7. Konus-Wind detection of GRB 220412B
  8. GRB 220412B: Fermi GBM observation
  9. Konus-Wind detection of GRB 220403C
  10. Konus-Wind detection of GRB 220408B
  11. GRB 220412A: Swift-BAT refined analysis
  12. GRB 220408B: Fermi-LAT detection
  13. GRB 220412A: Swift-XRT refined Analysis
  14. GRB 220412A: Enhanced Swift-XRT position
  15. GRB 220412A: Swift/UVOT Upper Limits
  16. GRB 220408A: GRANDMA observations
  17. GRB 220412A: Swift detection of a burst
  18. Swift GRB220412.28: Global MASTER-Net observations report
  19. GRB 220411A: AstroSat CZTI detection
  20. IPN triangulation of GRB 220408B
  21. IPN triangulation of GRB 220403C
  22. Fermi GRB 220411A: Global MASTER-Net observations report
  23. GRB 220411A: BALROG localization (Fermi Trigger 671354405/ GRB 220411306)
  24. GRB 220411A: Fermi GBM Final Real-time Localization
  25. GRB 220408A: LOAO, DOAO, and, SAO optical upper limit
  26. GRB 220408B: AstroSat CZTI detection
  27. GRB 220408A: Swift-XRT refined Analysis
  28. Fermi GRB 220408B: Global MASTER-Net observations report
  29. GRB 220408A: Fermi GBM observation
  30. Chandra upper limit at the location of GRB 220408A
  31. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  32. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
  33. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  34. GRB 220403B: Mondy optical upper limit
  35. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  36. GRB 220403B: 1.5m OSN optical observation
  37. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  38. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  39. IceCube Alert 220405.21: Global MASTER-Net observations report
  40. GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  41. GRB 220403B: Fermi GBM detection
  42. GRB 220404A: Swift detection of a burst
  43. GRB 220403C (or A): Swift/BAT-GUANO detection outside the coded FOV
  44. GRB 220403B: Swift detection of a burst with an optical counterpart
  45. GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
  46. Swift GRB220402.16: Global MASTER-Net observations report
  47. Fermi GRB 220401B: Global MASTER-Net observations report
  48. Fermi GRB 220330A: Global MASTER-Net observations report
  49. Konus-Wind observation of GRB 220320A
  50. GRB 220325A: 1.3m DFOT Optical upper limit
  51. GRB 220324A: AstroSat CZTI detection
  52. GRB 220323A: AstroSat CZTI detection
  53. GRB 220316A: AstroSat CZTI detection
  54. GRB 220320A: AstroSat CZTI detection
  55. GRB 220319A: LCO Optical Upper Limit
  56. GRB 220319A: Swift-XRT refined Analysis
  57. GRB 220319A: MASTER Global Robotic Net optical observations
  58. GRB 220319A: Swift detection of a burst
  59. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  60. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
  61. IceCube-220317A: MASTER Global Robotic Net optical observations
  62. GRB 220310C: Swift-XRT observations
  63. Konus-Wind detection of GRB 220310A
  64. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  65. GRB 220311A: A long GRB detected by INTEGRAL
  66. Integral GRB220311.69: Global MASTER-Net observations report
  67. GRB 220308A: AGILE detection
  68. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  69. GRB 220310A: MAXI/GSC detection
  70. Konus-Wind detection of GRB 220308A
  71. Fermi GRB 220309A: Global MASTER-Net observations report
  72. GRB 220308A: Swift/BAT-GUANO detection outside the coded FOV
  73. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  74. IPN triangulation of GRB 220305B
  75. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  76. GRB 220306B: BOOTES-1 optical upper limit
  77. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  78. GRB 220306A: Fermi GBM Final Real-time Localization
  79. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  80. IceCube Alert 220304.74: Global MASTER-Net observations report
  81. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  82. Fermi GRB 220304A: Global MASTER-Net observations report
  83. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  84. GRB 220302A: Swift detection of a burst
  85. GRB 220228A: Fermi-LAT detection
  86. Konus-Wind detection of GRB 220222A
  87. IceCube-220225A: Upper limits from a search for additional neutrino events in IceCube
  88. Fermi trigger No 667737010: Global MASTER-Net observations report
  89. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  90. IceCube Alert 220225.59: Global MASTER-Net observations report
  91. ZTF22aaajecp/AT2022cmc: DECam Photometry
  92. Konus-Wind observation of GRB 220219B
  93. Fermi GRB 220223A: Global MASTER-Net observations report
  94. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  95. IceCube-220221A: Upper limits from a search for additional neutrino events in IceCube
  96. GRB 220222A: Swift/BAT-GUANO detection outside the coded FOV
  97. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  98. ZTF22aabjpxh/AT2022cva: Assy optical observations
  99. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  100. Konus-Wind observation of GRB 220219A

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