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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"

11519 results found.

  1. Fermi GRB 220512A: Global MASTER-Net observations report
  2. GRB 220512A: Fermi GBM Final Real-time Localization
  3. GRB 220511A: Swift/BAT-GUANO arcminute localization
  4. Fermi GRB 220511A: Global MASTER-Net observations report
  5. GRB 220511A: AGILE detection
  6. GRB 220511A: BALROG localization (Fermi Trigger 673969321/ GRB 220511571)
  7. GRB 220511A: Fermi GBM Final Real-time Localization
  8. GRB 220507A: AstroSat CZTI detection
  9. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  10. Fermi trigger No 673846271: Global MASTER-Net observations report
  11. IceCube-220509A - IceCube observation of a high-energy neutrino candidate track-like event
  12. GRB 220508A: Fermi GBM Final Real-time Localization
  13. GRB 220507A: Fermi GBM Final Localization
  14. Fermi trigger No 673610950: Global MASTER-Net observations report
  15. Fermi-LAT Gamma-ray Observations of IceCube-220501A
  16. GRB 220501A: BOOTES-1 optical upper limit
  17. GRB 220501A: Fermi GBM observation
  18. IceCube-220501A - IceCube observation of a high-energy neutrino candidate track-like event
  19. GRB 220501A: GRANDMA/TJML Optical Observations
  20. GRB 220501A: Fermi GBM Final Real-time Localization
  21. GRB 220426A: Swift-XRT and UVOT observations
  22. Konus-Wind detection of GRB 220426A
  23. IPN triangulation of GRB 220426A
  24. Fermi GRB 220426A: Global MASTER-Net observations report
  25. GRB 220426A: Fermi GBM detection
  26. GRB 220426A: Swift/BAT-GUANO detection outside the coded FOV
  27. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  28. Fermi GRB 220426B: Global MASTER-Net observations report
  29. GRB 220426B: Fermi GBM Final Real-time Localization
  30. GRB 220426A: BALROG localization (Fermi Trigger 672648596/ GRB 220426285)
  31. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  32. Fermi trigger No 672492774: Global MASTER-Net observations report
  33. IceCube-220425A - IceCube observation of a high-energy neutrino candidate track-like event
  34. IceCube-220424A - IceCube observation of a high-energy neutrino candidate track-like event
  35. Fermi trigger No 672374264: Global MASTER-Net observations report
  36. GRB 220421A: Fermi GBM observation
  37. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  38. GRB 220421A: Swift/BAT-GUANO detection outside the coded FOV
  39. Fermi trigger No 672221879: Global MASTER-Net observations report
  40. Fermi GBM trigger 672128054/220420260 is not a GRB
  41. IceCube-220421A - IceCube observation of a high-energy neutrino candidate track-like event
  42. GRB 220418B Fermi GBM observation
  43. Fermi trigger No 672093919: Global MASTER-Net observations report
  44. GRB 220417A: Fermi GBM detection
  45. IPN triangulation of GRB 220411A
  46. GRB 220418B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  47. GRB 220417A: Swift/BAT-GUANO detection outside the coded FOV
  48. Fermi GRB 220418A: Global MASTER-Net observations report
  49. GRB 220418B: Fermi GBM Final Real-time Localization
  50. GRB 220418A: Fermi GBM Final Real-time Localization
  51. Fermi GRB 220417A: Global MASTER-Net observations report
  52. GRB 220417A: Fermi GBM Final Real-time Localization
  53. Fermi trigger No 671729344: Global MASTER-Net observations report
  54. Konus-Wind detection of GRB 220412B
  55. GRB 220412B: Fermi GBM observation
  56. GRB 220408B: Fermi GBM observation
  57. Konus-Wind detection of GRB 220408B
  58. GRB 220408B: Fermi-LAT detection
  59. GRB 220408A: HCT optical upper limit
  60. GRB 220411A: AstroSat CZTI detection
  61. IPN triangulation of GRB 220408B
  62. IPN triangulation of GRB 220403C
  63. Fermi GRB 220411A: Global MASTER-Net observations report
  64. GRB 220411A: BALROG localization (Fermi Trigger 671354405/ GRB 220411306)
  65. GRB 220411A: Fermi GBM Final Real-time Localization
  66. GRB 220403B: 1.3m DFOT Optical upper limit
  67. GRB 220408A: 1.3m DFOT Optical upper limit
  68. GRB 220408A: LOAO, DOAO, and, SAO optical upper limit
  69. GRB 220403C: Swift-XRT observations
  70. GRB 220408A: redshift lower limit estimating
  71. GRB 220408A: NOT optical observations and archival detection
  72. GRB 220408B: AstroSat CZTI detection
  73. GRB 220408A: LCO Optical Afterglow Detection
  74. GRB 220403C: Swift ToO observations
  75. GRB 220408A: BOOTES-5/JGT optical afterglow detection
  76. Fermi GRB 220408B: Global MASTER-Net observations report
  77. GRB 220408A: GIT optical upper limit
  78. GRB 220408A: Fermi GBM observation
  79. GRB 220408B: Fermi GBM Final Localization
  80. GRB 220408A: Xinglong-2.16m optical upper limit
  81. Chandra upper limit at the location of GRB 220408A
  82. GRB 220408A: KAIT Optical Observations
  83. Fermi GRB 220408A: Global MASTER-Net observations report
  84. GRB 220408A: Fermi GBM Final Real-time Localization
  85. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  86. GRB 220403B: 1.5m OSN optical observation
  87. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  88. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  89. GRB 220405A: Fermi GBM Final Localization
  90. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  91. GRB 220404B: Fermi GBM Final Real-time Localization
  92. GRB 220403B: Fermi GBM detection
  93. GRB 220403C (or A): Swift/BAT-GUANO detection outside the coded FOV
  94. Fermi GRB 220403A: Global MASTER-Net observations report
  95. GRB 220403A: Fermi GBM Final Real-time Localization
  96. GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
  97. GRB 220401A: Fermi GBM observation
  98. Fermi GRB 220401B: Global MASTER-Net observations report
  99. GRB 220401B: Fermi GBM Final Real-time Localization
  100. GRB 220401A: Fermi GBM Final Localization

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