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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"

11523 results found.

  1. GRB 210520A: Fermi GBM Final Real-time Localization
  2. Fermi GBM observation of a bright burst from magneta
  3. Fermi GRB 210519A: Global MASTER-Net observations report
  4. IPN triangulation of GRB 210518A
  5. Fermi trigger No 643065622: Global MASTER-Net observations report
  6. GRB 210518.889: DDOTI Upper Limits on the Afterglow
  7. GRB 210519A: Fermi GBM Final Localization
  8. Fermi GRB 210518A: Global MASTER-Net observations report
  9. Fermi trigger No 642991619: Global MASTER-Net observations report
  10. Fermi-LAT Gamma-ray Observations of IceCube-210516A
  11. GRB 210518A: Fermi GBM Final Real-time Localization
  12. Fermi GRB 210516A: Global MASTER-Net observations report
  13. GRB 210516A: Fermi GBM Final Real-time Localization
  14. IceCube-210516A - IceCube observation of a high-energy neutrino candidate track-like event
  15. Fermi GRB 210515B: Global MASTER-Net observations report
  16. Fermi GRB 210515A: Global MASTER-Net observations report
  17. GRB 210515B: Fermi GBM Final Real-time Localization
  18. GRB 210515A: Fermi GBM Final Real-time Localization
  19. Konus-Wind detection of GRB 210511B
  20. GRB 210512.786: DDOTI Upper Limits on the Afterglow
  21. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  22. Fermi trigger No 642538568: Global MASTER-Net observations report
  23. IPN triangulation of GRB 210511B
  24. IceCube-210510A: not observable by Fermi-GBM
  25. GRB 210511B: DDOTI Upper Limits on the Afterglow
  26. IPN triangulation of GRB 210427A
  27. GRB 210511B: Fermi GBM observation
  28. Fermi-LAT Gamma-ray Observations of IceCube-210510A
  29. Fermi GRB 210511A: Global MASTER-Net observations report
  30. Fermi GRB 210510A: DDOTI Upper Limits on the Afterglow
  31. Fermi GRB 210511B: Global MASTER-Net observations report
  32. GRB 210511B: AGILE detection
  33. GRB 210511B: GECAM detection
  34. GRB 210511B: BALROG localization (Fermi Trigger 642425204 / GRB 210511477)
  35. GRB 210511B: Fermi GBM Final Real-time Localization
  36. GRB 210511A: Fermi GBM Final Real-time Localization
  37. Fermi GRB 210510A: Global MASTER-Net observations report
  38. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  39. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  40. GRB 210510A: Fermi GBM Final Real-time Localization
  41. IceCube-210510A - IceCube observation of a high-energy neutrino candidate track-like event
  42. IPN triangulation of GRB 210506A
  43. Fermi GRB 210507A: Global MASTER-Net observations report
  44. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  45. GRB 210507A: Fermi GBM Final Real-time Localization
  46. IceCube-210503A: IceCube observation of a high-energy neutrino candidate event
  47. Fermi GRB 210503A: DDOTI Upper Limits on the Afterglow
  48. Fermi GRB 210503A: Global MASTER-Net observations report
  49. GRB 210503A: Fermi GBM Final Real-time Localization
  50. Fermi GRB 210501A: Global MASTER-Net observations report
  51. Fermi trigger No 641601187: Global MASTER-Net observations report
  52. GRB 210501A: Fermi GBM Final Real-time Localization
  53. Fermi GRB 210430B: Global MASTER-Net observations report
  54. GRB 210430B: Fermi GBM Final Real-time Localization
  55. IPN triangulation of GRB 210424B (short/hard)
  56. GRB 210427A: GECAM detection
  57. GRB 210427A: BALROG localization (Fermi Trigger / GRB 210427206)
  58. Fermi GRB 210427A: Global MASTER-Net observations report
  59. GRB 210427A: Fermi GBM Final Real-time Localization
  60. GRB 210422B: Fermi GBM Final Localization
  61. Fermi trigger No 640975205: Global MASTER-Net observations report
  62. GRB 210424.694: DDOTI Upper Limits on the Afterglow
  63. GRB 210424A: Fermi GBM Final Real-time Localization
  64. GRB 210421B: AstroSat CZTI detection
  65. GRB 210421B: AstroSat CZTI detection
  66. GRB 210419B: AstroSat CZTI detection
  67. Fermi Gamma-ray Burst Monitor trigger 210421C is not a GRB
  68. GRB 210421B: Swift/BAT-GUANO detection and arcminute localization
  69. Fermi GRB 210421C: Global MASTER-Net observations report
  70. GRB 210421C: Fermi GBM Final Real-time Localization
  71. GRB 210421B: Fermi GBM Final Localization
  72. Fermi trigger No 640695289: Global MASTER-Net observations report
  73. GRB 210413B: MITSuME Okayama optical upper limits
  74. Fermi GRB 210420A: Global MASTER-Net observations report
  75. GRB 210420A: Fermi GBM Final Real-time Localization
  76. Fermi GRB 210419B: Global MASTER-Net observations report
  77. GRB 210419B: Fermi GBM Final Real-time Localization
  78. Fermi GBM trigger 640353092/210417494 is not a GRB
  79. Fermi Gamma-ray Burst Monitor trigger 640303939/210416925 is not a GRB
  80. GRB 210413B: Swift/BAT detection and probable localization of a short burst
  81. GRB 210411B: AstroSat CZTI detection
  82. GRB 210410A: AstroSat CZTI detection
  83. GRB 210410A: A twin of short GRB 090510 with complementary observations
  84. Fermi GRB 210415A: Global MASTER-Net observations report
  85. GRB 210415A: Fermi GBM Final Real-time Localization
  86. GRB 210410A: MITSuME Akeno optical upper limits
  87. Fermi GRB 210411B: Global MASTER-Net observations report
  88. Konus-Wind detection of GRB 210410A
  89. GRB 210411D: BALROG localization (Fermi Trigger 639851475 / GRB 210411688)
  90. GRB 210411D: Fermi GBM Final Real-time Localization
  91. GRB 210411B: Fermi GBM Final Real-time Localization
  92. Fermi GRB 210411A: Global MASTER-Net observations report
  93. GRB 210411A: Fermi GBM Final Real-time Localization
  94. GRB 210410A: Fermi GBM detection
  95. GRB 210410A: Swift/UVOT Upper Limits
  96. GRB210410A: Joint inspection of RATIR and D50 data
  97. GRB 210410A: RATIR Optical and NIR Observations
  98. GRB 210410A: AGILE detection of a burst
  99. GRB 210410A: Fermi-LAT detection
  100. GRB210410A: Candidate optical afterglow by Ondrejov D50

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