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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"

11546 results found.

  1. Fermi GRB 210529B: Global MASTER-Net observations report
  2. GRB 210529B: Fermi GBM Final Real-time Localization
  3. GRB 210529A: Fermi GBM Final Real-time Localization
  4. GRB 210528A: Fermi GBM detection
  5. GRB 210528A: AstroSat CZTI detection
  6. Fermi GRB 210528A: Global MASTER-Net observations report
  7. GRB 210528A: BALROG localization (Fermi Trigger 643903431 / GRB 210528586)
  8. GRB 210528A: Fermi GBM Final Real-time Localization
  9. Fermi GRB 210524B: DDOTI Upper Limits on the Afterglow
  10. Konus-Wind detection of GRB 210524A
  11. IPN triangulation of GRB 210524A
  12. Fermi trigger No 643548039: Global MASTER-Net observations report
  13. GRB 210524B: Fermi GBM Final Real-time Localization
  14. GRB 210524A: BALROG localization (Fermi Trigger 643525204 / GRB 210524208)
  15. Fermi GRB 210524A: Global MASTER-Net observations report
  16. GRB 210524A: Fermi GBM Final Real-time Localization
  17. GRB 210522A: GECAM detection
  18. GRB 210520A: Swift-XRT observations
  19. GRB 210520A: Fermi GBM detection
  20. GRB 210520A: Tiled Swift observations
  21. GRB 210520A: Fermi-LAT detection
  22. GRB 210520A: GECAM detection
  23. Fermi GRB 210520A: Global MASTER-Net observations report
  24. GRB 210520A: Fermi GBM Final Real-time Localization
  25. Fermi GBM observation of a bright burst from magneta
  26. Fermi GRB 210519A: Global MASTER-Net observations report
  27. IPN triangulation of GRB 210518A
  28. Fermi trigger No 643065622: Global MASTER-Net observations report
  29. GRB 210518.889: DDOTI Upper Limits on the Afterglow
  30. GRB 210519A: Fermi GBM Final Localization
  31. Fermi GRB 210518A: Global MASTER-Net observations report
  32. Fermi trigger No 642991619: Global MASTER-Net observations report
  33. Fermi-LAT Gamma-ray Observations of IceCube-210516A
  34. GRB 210518A: Fermi GBM Final Real-time Localization
  35. Fermi GRB 210516A: Global MASTER-Net observations report
  36. GRB 210516A: Fermi GBM Final Real-time Localization
  37. IceCube-210516A - IceCube observation of a high-energy neutrino candidate track-like event
  38. Fermi GRB 210515B: Global MASTER-Net observations report
  39. Fermi GRB 210515A: Global MASTER-Net observations report
  40. GRB 210515B: Fermi GBM Final Real-time Localization
  41. GRB 210515A: Fermi GBM Final Real-time Localization
  42. Konus-Wind detection of GRB 210511B
  43. GRB 210512.786: DDOTI Upper Limits on the Afterglow
  44. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  45. Fermi trigger No 642538568: Global MASTER-Net observations report
  46. IPN triangulation of GRB 210511B
  47. IceCube-210510A: not observable by Fermi-GBM
  48. GRB 210511B: DDOTI Upper Limits on the Afterglow
  49. IPN triangulation of GRB 210427A
  50. GRB 210511B: Fermi GBM observation
  51. Fermi-LAT Gamma-ray Observations of IceCube-210510A
  52. Fermi GRB 210511A: Global MASTER-Net observations report
  53. Fermi GRB 210510A: DDOTI Upper Limits on the Afterglow
  54. Fermi GRB 210511B: Global MASTER-Net observations report
  55. GRB 210511B: AGILE detection
  56. GRB 210511B: GECAM detection
  57. GRB 210511B: BALROG localization (Fermi Trigger 642425204 / GRB 210511477)
  58. GRB 210511B: Fermi GBM Final Real-time Localization
  59. GRB 210511A: Fermi GBM Final Real-time Localization
  60. Fermi GRB 210510A: Global MASTER-Net observations report
  61. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  62. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  63. GRB 210510A: Fermi GBM Final Real-time Localization
  64. IceCube-210510A - IceCube observation of a high-energy neutrino candidate track-like event
  65. IPN triangulation of GRB 210506A
  66. Fermi GRB 210507A: Global MASTER-Net observations report
  67. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  68. GRB 210507A: Fermi GBM Final Real-time Localization
  69. IceCube-210503A: IceCube observation of a high-energy neutrino candidate event
  70. Fermi GRB 210503A: DDOTI Upper Limits on the Afterglow
  71. Fermi GRB 210503A: Global MASTER-Net observations report
  72. GRB 210503A: Fermi GBM Final Real-time Localization
  73. Fermi GRB 210501A: Global MASTER-Net observations report
  74. Fermi trigger No 641601187: Global MASTER-Net observations report
  75. GRB 210501A: Fermi GBM Final Real-time Localization
  76. Fermi GRB 210430B: Global MASTER-Net observations report
  77. GRB 210430B: Fermi GBM Final Real-time Localization
  78. IPN triangulation of GRB 210424B (short/hard)
  79. GRB 210427A: GECAM detection
  80. GRB 210427A: BALROG localization (Fermi Trigger / GRB 210427206)
  81. Fermi GRB 210427A: Global MASTER-Net observations report
  82. GRB 210427A: Fermi GBM Final Real-time Localization
  83. GRB 210422B: Fermi GBM Final Localization
  84. Fermi trigger No 640975205: Global MASTER-Net observations report
  85. GRB 210424.694: DDOTI Upper Limits on the Afterglow
  86. GRB 210424A: Fermi GBM Final Real-time Localization
  87. GRB 210421B: AstroSat CZTI detection
  88. GRB 210421B: AstroSat CZTI detection
  89. GRB 210419B: AstroSat CZTI detection
  90. Fermi Gamma-ray Burst Monitor trigger 210421C is not a GRB
  91. GRB 210421B: Swift/BAT-GUANO detection and arcminute localization
  92. Fermi GRB 210421C: Global MASTER-Net observations report
  93. GRB 210421C: Fermi GBM Final Real-time Localization
  94. GRB 210421B: Fermi GBM Final Localization
  95. Fermi trigger No 640695289: Global MASTER-Net observations report
  96. GRB 210413B: MITSuME Okayama optical upper limits
  97. Fermi GRB 210420A: Global MASTER-Net observations report
  98. GRB 210420A: Fermi GBM Final Real-time Localization
  99. Fermi GRB 210419B: Global MASTER-Net observations report
  100. GRB 210419B: Fermi GBM Final Real-time Localization

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