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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"

11516 results found.

  1. GRB 211211A: Fermi GBM Final Real-time Localization
  2. Fermi trigger No 660868196: Global MASTER-Net observations report
  3. Fermi trigger No 660736561: Global MASTER-Net observations report
  4. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  5. Fermi-LAT Gamma-ray Observations of IceCube-211208A
  6. IceCube-211208A - IceCube observation of a high-energy neutrino candidate track-like event
  7. GRB 211204C: Fermi GBM detection
  8. GRB 211206A: Not observable by Fermi-GBM
  9. GRB 211204C: AstroSat CZTI detection
  10. IPN triangulation of GRB 211204C
  11. GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV
  12. GRB 211204C: GECAM detection
  13. Fermi GRB 211204C: Global MASTER-Net observations report
  14. GRB 211204C: Fermi GBM Final Real-time Localization
  15. Fermi GRB 211204B: Global MASTER-Net observations report
  16. GRB 211204B: Fermi GBM Final Real-time Localization
  17. Fermi GRB 211204A: Global MASTER-Net observations report
  18. GRB 211204A: Fermi GBM Final Real-time Localization
  19. GRB 211124A: Fermi GBM Observation
  20. Fermi GBM Upper limits for GRB 211203A
  21. Konus-Wind detection of GRB 211130A
  22. IPN triangulation of GRB 211130A
  23. GRB 211201A: GECAM detection
  24. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  25. Fermi GRB 211201A: Global MASTER-Net observations report
  26. GRB 211201A: Fermi GBM Final Real-time Localization
  27. Fermi GRB 211130A: Global MASTER-Net observations report
  28. GRB 211130A: BALROG localization (Fermi Trigger 659978192 / GRB 211130636)
  29. GRB 211130A: Fermi GBM Final Real-time Localization
  30. GRB 211106A: GECAM detection
  31. GRB 211129A: Fermi GBM observation
  32. IPN triangulation of GRB 211118A
  33. GRB 211023A: Xinglong 2.16m optical observations
  34. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  35. GRB 211120548: Fermi GBM observation
  36. IceCube-211125A: IceCube observation of a high-energy neutrino candidate track-like event
  37. GRB 211118A: Fermi GBM detection
  38. Fermi-LAT Gamma-ray Observations of IceCube-211123A
  39. IceCube-211123A: Upper limits from Fermi-GBM Observations
  40. IceCube-211117A: not observable by Fermi-GBM
  41. IceCube-211116A: not observable by Fermi-GBM
  42. IceCube-211023A: not observable by Fermi-GBM
  43. IPN triangulation of GRB 211124A (short)
  44. HAWC-211123A: not observable by Fermi-GBM
  45. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  46. IceCube-211123A - IceCube observation of a high-energy neutrino candidate track-like event
  47. Fermi trigger No 659413798: Global MASTER-Net observations report
  48. Fermi trigger No 659183098: Global MASTER-Net observations report
  49. Fermi trigger No 659106591: Global MASTER-Net observations report
  50. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  51. GRB 211023A: optical observations and photometric evidence of supernova
  52. Fermi-LAT Gamma-ray Observations of IceCube-211117A
  53. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  54. Fermi trigger No 658971499: Global MASTER-Net observations report
  55. IceCube-211117A : IceCube observation of a high-energy neutrino candidate track-like event
  56. Fermi-LAT Gamma-ray Observations of IceCube-211116A
  57. Fermi trigger No 658755664: Global MASTER-Net observations report
  58. Fermi trigger No 658764238: Global MASTER-Net observations report
  59. IceCube-211116A : IceCube observation of a high-energy neutrino candidate track-like event
  60. GRB 211115A: CALET Gamma-Ray Burst Monitor detection
  61. Fermi trigger No 658686687: Global MASTER-Net observations report
  62. GRB 211023A: classification and SPI-ACS/INTEGRAL registration
  63. Fermi GRB 211112A: Global MASTER-Net observations report
  64. GRB 211106A: Swift/UVOT upper limits
  65. IPN triangulation of GRB 211106A (short)
  66. GRB 211112A: Fermi GBM Final Real-time Localization
  67. Fermi trigger No 658214822: Global MASTER-Net observations report
  68. GRB 211107A: GECAM detection
  69. Fermi GRB 211109B: Global MASTER-Net observations report
  70. GRB 211023A: SAO RAS optical observations
  71. GRB 211109B: Fermi GBM Final Real-time Localization
  72. Fermi GRB 211109A: Global MASTER-Net observations report
  73. GRB 211109A: Fermi GBM Final Real-time Localization
  74. Fermi GBM Sub-Threshold Detection of GRB 211106A
  75. GRB 211107A: Fermi GBM Final Real-time Localization
  76. Fermi GBM trigger 657780594/211105201 is not a GRB
  77. GRB 211023A: optical detection by SBT in Ondrejov
  78. GRB 211023A: continued 1.3m DFOT Optical Observations and possible jet break
  79. Fermi trigger No 657742914: Global MASTER-Net observations report
  80. GRB 211104A: Fermi GBM Final Real-time Localization
  81. GRB 211024A: MITSuME Akeno optical observation
  82. GRB 211102B: GECAM detection
  83. Fermi GRB 211102A: Global MASTER-Net observations report
  84. GRB 211102B: BALROG localization (Fermi Trigger 657554740 / GRB 211102587)
  85. GRB 211102B: Fermi GBM Final Real-time Localization
  86. GRB 211102A: BALROG localization (Fermi Trigger 657533168 / GRB 211102338)
  87. GRB 211102A: Fermi GBM Final Real-time Localization
  88. GRB 211024A: 1.3m DFOT observations
  89. Fermi GRB 211031A: Global MASTER-Net observations report
  90. GRB 211031A: Fermi GBM Final Real-time Localization
  91. GRB 211023A: 1.3m DFOT Optical Observations
  92. Konus-Wind detection of GRB 211023A
  93. GRB 211023A: Terskol optical observations
  94. GRB 211023A: continued Mondy optical observations
  95. GRB 211024A: Swift-XRT source 4 is not an afterglow.
  96. Fermi GRB 211027A: Global MASTER-Net observations report
  97. GRB 211024A: Possible afterglow candidate from GIT
  98. GRB 211027A: Fermi GBM Final Real-time Localization
  99. GRB 211024A: Fermi GBM detection
  100. GRB 211018A: Swift-XRT observations

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