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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"

11522 results found.

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

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