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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"

11109 results found.

  1. IceCube-220509A - IceCube observation of a high-energy neutrino candidate track-like event
  2. GRB 220508A: Fermi GBM Final Real-time Localization
  3. GRB 220507A: Fermi GBM Final Localization
  4. Fermi trigger No 673610950: Global MASTER-Net observations report
  5. Fermi-LAT Gamma-ray Observations of IceCube-220501A
  6. GRB 220501A: BOOTES-1 optical upper limit
  7. GRB 220501A: Fermi GBM observation
  8. IceCube-220501A - IceCube observation of a high-energy neutrino candidate track-like event
  9. GRB 220501A: GRANDMA/TJML Optical Observations
  10. GRB 220501A: Fermi GBM Final Real-time Localization
  11. GRB 220426A: Swift-XRT and UVOT observations
  12. Konus-Wind detection of GRB 220426A
  13. IPN triangulation of GRB 220426A
  14. Fermi GRB 220426A: Global MASTER-Net observations report
  15. GRB 220426A: Fermi GBM detection
  16. GRB 220426A: Swift/BAT-GUANO detection outside the coded FOV
  17. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  18. Fermi GRB 220426B: Global MASTER-Net observations report
  19. GRB 220426B: Fermi GBM Final Real-time Localization
  20. GRB 220426A: BALROG localization (Fermi Trigger 672648596/ GRB 220426285)
  21. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  22. Fermi trigger No 672492774: Global MASTER-Net observations report
  23. IceCube-220425A - IceCube observation of a high-energy neutrino candidate track-like event
  24. IceCube-220424A - IceCube observation of a high-energy neutrino candidate track-like event
  25. Fermi trigger No 672374264: Global MASTER-Net observations report
  26. GRB 220421A: Fermi GBM observation
  27. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  28. GRB 220421A: Swift/BAT-GUANO detection outside the coded FOV
  29. Fermi trigger No 672221879: Global MASTER-Net observations report
  30. Fermi GBM trigger 672128054/220420260 is not a GRB
  31. IceCube-220421A - IceCube observation of a high-energy neutrino candidate track-like event
  32. GRB 220418B Fermi GBM observation
  33. Fermi trigger No 672093919: Global MASTER-Net observations report
  34. GRB 220417A: Fermi GBM detection
  35. IPN triangulation of GRB 220411A
  36. GRB 220418B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  37. GRB 220417A: Swift/BAT-GUANO detection outside the coded FOV
  38. Fermi GRB 220418A: Global MASTER-Net observations report
  39. GRB 220418B: Fermi GBM Final Real-time Localization
  40. GRB 220418A: Fermi GBM Final Real-time Localization
  41. Fermi GRB 220417A: Global MASTER-Net observations report
  42. GRB 220417A: Fermi GBM Final Real-time Localization
  43. Fermi trigger No 671729344: Global MASTER-Net observations report
  44. Konus-Wind detection of GRB 220412B
  45. GRB 220412B: Fermi GBM observation
  46. GRB 220408B: Fermi GBM observation
  47. Konus-Wind detection of GRB 220408B
  48. GRB 220408B: Fermi-LAT detection
  49. GRB 220408A: HCT optical upper limit
  50. GRB 220411A: AstroSat CZTI detection
  51. IPN triangulation of GRB 220408B
  52. IPN triangulation of GRB 220403C
  53. Fermi GRB 220411A: Global MASTER-Net observations report
  54. GRB 220411A: BALROG localization (Fermi Trigger 671354405/ GRB 220411306)
  55. GRB 220411A: Fermi GBM Final Real-time Localization
  56. GRB 220403B: 1.3m DFOT Optical upper limit
  57. GRB 220408A: 1.3m DFOT Optical upper limit
  58. GRB 220408A: LOAO, DOAO, and, SAO optical upper limit
  59. GRB 220403C: Swift-XRT observations
  60. GRB 220408A: redshift lower limit estimating
  61. GRB 220408A: NOT optical observations and archival detection
  62. GRB 220408B: AstroSat CZTI detection
  63. GRB 220408A: LCO Optical Afterglow Detection
  64. GRB 220403C: Swift ToO observations
  65. GRB 220408A: BOOTES-5/JGT optical afterglow detection
  66. Fermi GRB 220408B: Global MASTER-Net observations report
  67. GRB 220408A: GIT optical upper limit
  68. GRB 220408A: Fermi GBM observation
  69. GRB 220408B: Fermi GBM Final Localization
  70. GRB 220408A: Xinglong-2.16m optical upper limit
  71. Chandra upper limit at the location of GRB 220408A
  72. GRB 220408A: KAIT Optical Observations
  73. Fermi GRB 220408A: Global MASTER-Net observations report
  74. GRB 220408A: Fermi GBM Final Real-time Localization
  75. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  76. GRB 220403B: 1.5m OSN optical observation
  77. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  78. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  79. GRB 220405A: Fermi GBM Final Localization
  80. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  81. GRB 220404B: Fermi GBM Final Real-time Localization
  82. GRB 220403B: Fermi GBM detection
  83. GRB 220403C (or A): Swift/BAT-GUANO detection outside the coded FOV
  84. Fermi GRB 220403A: Global MASTER-Net observations report
  85. GRB 220403A: Fermi GBM Final Real-time Localization
  86. GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
  87. GRB 220401A: Fermi GBM observation
  88. Fermi GRB 220401B: Global MASTER-Net observations report
  89. GRB 220401B: Fermi GBM Final Real-time Localization
  90. GRB 220401A: Fermi GBM Final Localization
  91. Fermi trigger No 670501065: Global MASTER-Net observations report
  92. Fermi Gamma-ray Burst Monitor trigger 220331776/670444627 is not a GRB
  93. GRB 220331A: Fermi GBM Final Real-time Localization
  94. Fermi GRB 220330A: Global MASTER-Net observations report
  95. GRB 220330A: Fermi GBM Final Real-time Localization
  96. GRB 220320A: Detection by VZLUSAT-2
  97. GRB 220326A: Fermi GBM Final Localization
  98. GRB 220325A: 1.3m DFOT Optical upper limit
  99. GRB 220325B: Fermi GBM Final Localization
  100. Fermi GBM Sub-Threshold Detection of GRB 220325A

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