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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

27964 results found.

  1. Swift GRB 210820A: Global MASTER-Net observations report
  2. GRB 210820B: Fermi GBM Final Localization
  3. GRB 210820A: Swift detection of a burst with an optical counterpart
  4. Swift GRB210818.68: Global MASTER-Net observations report
  5. Swift GRB 210818A: Global MASTER-Net observations report
  6. GRB 210818A: Swift-XRT refined Analysis
  7. GRB 210818A: Swift-BAT refined analysis
  8. GRB 210726A: VLA radio afterglow detection
  9. Konus-Wind detection of GRB 210818A
  10. Swift Trigger 1069242 is Cyg X-1
  11. GRB 210818A: AstroSat CZTI detection
  12. GRB 210818A: AGILE detection
  13. GRB 210818A: Enhanced Swift-XRT position
  14. GRB 210818A: Swift detection of a burst with an optical counterpart
  15. GRB 210815A: Fermi GBM Final Real-time Localization
  16. GRB 210712A: Fermi GBM observation
  17. GRB 210813A: Fermi GBM Final Real-time Localization
  18. GRB 210812B: Fermi GBM Final Real-time Localization
  19. GRB 210812A: Fermi GBM Final Real-time Localization
  20. GRB 080102A: Fermi GBM Final Real-time Localization
  21. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  22. GRB 080101A: Fermi GBM Final Real-time Localization
  23. GRB 210730A: Tautenburg observations
  24. IceCube-210811A - IceCube observation of a high-energy neutrino candidate track-like event
  25. GRB 210807C: Swift-BAT refined analysis
  26. GRB 210807A: Detection by GRBAlpha
  27. GRB 210807A: Swift-BAT refined analysis
  28. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  29. GRB 210807C: Swift-XRT refined Analysis
  30. GRB 210807C: Fermi GBM detection
  31. GRB 210807C: Swift/UVOT Upper Limits
  32. GRB 210807A: Swift/UVOT Detection
  33. GRB 210807A: Swift-XRT refined Analysis
  34. GRB 210807C: Enhanced Swift-XRT position
  35. Swift GRB210807.74: Global MASTER-Net observations report
  36. Swift GRB210807.96: Global MASTER-Net observations report
  37. GRB 210807C: Swift detection of a burst
  38. GRB 210807C: Fermi GBM Final Real-time Localization
  39. Swift GRB 210807A: Global MASTER-Net observations report
  40. Swift GRB210807.79: Global MASTER-Net observations report
  41. Swift GRB210807.78: Global MASTER-Net observations report
  42. GRB 210807A: Enhanced Swift-XRT position
  43. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  44. GRB 210807B: Fermi GBM Final Real-time Localization
  45. GRB 210807A: Swift detection of a burst with an optical counterpart
  46. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 August 5
  47. IPN Triangulation of a bright burst from SGR 1935+2154
  48. GRB 210802A: BOOTES-2/TELMA optical upper limit
  49. GRB 210802A: Swift-XRT afterglow detection
  50. GRB 210802A: Fermi GBM detection
  51. GRB 210802A: Fermi-LAT detection
  52. GRB 210802A: Tiled Swift observations
  53. GRB 210801A: Fermi GBM detection
  54. GRB 210731A: continued GROND observations
  55. GRB 210731A: VLT/X-shooter redshift
  56. GRB 210731A: KAIT Optical Detection
  57. GRB 210731A: Swift-BAT refined analysis
  58. GRB 210731A: MASTER optical afterglow detection
  59. GRB 210731A: Swift-XRT refined Analysis
  60. GRB 210731A: GROND observations
  61. GRB 210731A: Fermi GBM Observation
  62. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  63. Swift GRB210731.62: Global MASTER-Net observations report
  64. GRB 210731A: MeerLICHT optical afterglow detection
  65. GRB210731A: Enhanced Swift-XRT position
  66. GRB 210731A: Swift detection of a burst
  67. Swift GRB210731.93: Global MASTER-Net observations report
  68. Trigger 1062273: Swift detection of 4U 1700-377
  69. GRB 210730A: BOOTES-5/JGT and 2.2m CAHA telescopes optical limit
  70. Swift GRB 210730A: Global MASTER-Net observations report
  71. IceCube-210730A - IceCube observation of a high-energy neutrino candidate track-like event
  72. GRB 210726A: Chandra detection of the X-ray afterglow
  73. GRB 210730A: Fermi GBM observation
  74. GRB 210730A: AstroSat CZTI detection
  75. GRB 210730A: Swift-BAT refined analysis
  76. GRB 210730A: Swift-XRT refined Analysis
  77. GRB 210730A: Swift/UVOT Upper Limits
  78. GRB 210724A: Early CAHA 2.2m limit
  79. GRB 210730A: Enhanced Swift-XRT position
  80. GRB 210727A: AstroSat CZTI detection
  81. GRB 210730A: Swift detection of a burst near M82
  82. GRB 210724A: Corrected Swift-XRT enhanced position
  83. Fermi GBM Sub-Threshold Detection of GRB 210725B
  84. GRB 210727A: CALET Gamma-Ray Burst Monitor detection
  85. IPN triangulation of GRB 210727A (short)
  86. Fermi GBM Sub-Threshold Detection of GRB 210726A
  87. GRB 210702A: MeerKAT radio detection
  88. GRB 210726A: Swift-XRT refined Analysis
  89. GRB 210726A: Swift-BAT refined analysis
  90. GRB 210726A: Likely a short burst
  91. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  92. GRB 210727A: AGILE/MCAL detection
  93. GRB 210725A: AbAO optical upper limit
  94. GRB 210724A: Swift/UVOT Upper Limits
  95. GRB 210723A: Swift/UVOT Upper Limits
  96. GRB 210725A: Swift/UVOT Upper Limits
  97. GRB 210725B: Swift/UVOT Upper Limits
  98. GRB 210726A: CAHA 2.2m telescope optical limit
  99. GRB 210726A: Enhanced Swift-XRT position
  100. GRB 210726A: Swift detection of a burst

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