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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"

27959 results found.

  1. GRB 210818A: Swift-XRT refined Analysis
  2. GRB 210818A: Swift-BAT refined analysis
  3. GRB 210726A: VLA radio afterglow detection
  4. Konus-Wind detection of GRB 210818A
  5. Swift Trigger 1069242 is Cyg X-1
  6. GRB 210818A: AstroSat CZTI detection
  7. GRB 210818A: AGILE detection
  8. GRB 210818A: Enhanced Swift-XRT position
  9. GRB 210818A: Swift detection of a burst with an optical counterpart
  10. GRB 210815A: Fermi GBM Final Real-time Localization
  11. GRB 210712A: Fermi GBM observation
  12. GRB 210813A: Fermi GBM Final Real-time Localization
  13. GRB 210812B: Fermi GBM Final Real-time Localization
  14. GRB 210812A: Fermi GBM Final Real-time Localization
  15. GRB 080102A: Fermi GBM Final Real-time Localization
  16. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  17. GRB 080101A: Fermi GBM Final Real-time Localization
  18. GRB 210730A: Tautenburg observations
  19. IceCube-210811A - IceCube observation of a high-energy neutrino candidate track-like event
  20. GRB 210807C: Swift-BAT refined analysis
  21. GRB 210807A: Detection by GRBAlpha
  22. GRB 210807A: Swift-BAT refined analysis
  23. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  24. GRB 210807C: Swift-XRT refined Analysis
  25. GRB 210807C: Fermi GBM detection
  26. GRB 210807C: Swift/UVOT Upper Limits
  27. GRB 210807A: Swift/UVOT Detection
  28. GRB 210807A: Swift-XRT refined Analysis
  29. GRB 210807C: Enhanced Swift-XRT position
  30. Swift GRB210807.74: Global MASTER-Net observations report
  31. Swift GRB210807.96: Global MASTER-Net observations report
  32. GRB 210807C: Swift detection of a burst
  33. GRB 210807C: Fermi GBM Final Real-time Localization
  34. Swift GRB 210807A: Global MASTER-Net observations report
  35. Swift GRB210807.79: Global MASTER-Net observations report
  36. Swift GRB210807.78: Global MASTER-Net observations report
  37. GRB 210807A: Enhanced Swift-XRT position
  38. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  39. GRB 210807B: Fermi GBM Final Real-time Localization
  40. GRB 210807A: Swift detection of a burst with an optical counterpart
  41. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 August 5
  42. IPN Triangulation of a bright burst from SGR 1935+2154
  43. GRB 210802A: BOOTES-2/TELMA optical upper limit
  44. GRB 210802A: Swift-XRT afterglow detection
  45. GRB 210802A: Fermi GBM detection
  46. GRB 210802A: Fermi-LAT detection
  47. GRB 210802A: Tiled Swift observations
  48. GRB 210801A: Fermi GBM detection
  49. GRB 210731A: continued GROND observations
  50. GRB 210731A: VLT/X-shooter redshift
  51. GRB 210731A: KAIT Optical Detection
  52. GRB 210731A: Swift-BAT refined analysis
  53. GRB 210731A: MASTER optical afterglow detection
  54. GRB 210731A: Swift-XRT refined Analysis
  55. GRB 210731A: GROND observations
  56. GRB 210731A: Fermi GBM Observation
  57. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  58. Swift GRB210731.62: Global MASTER-Net observations report
  59. GRB 210731A: MeerLICHT optical afterglow detection
  60. GRB210731A: Enhanced Swift-XRT position
  61. GRB 210731A: Swift detection of a burst
  62. Swift GRB210731.93: Global MASTER-Net observations report
  63. Trigger 1062273: Swift detection of 4U 1700-377
  64. GRB 210730A: BOOTES-5/JGT and 2.2m CAHA telescopes optical limit
  65. Swift GRB 210730A: Global MASTER-Net observations report
  66. IceCube-210730A - IceCube observation of a high-energy neutrino candidate track-like event
  67. GRB 210726A: Chandra detection of the X-ray afterglow
  68. GRB 210730A: Fermi GBM observation
  69. GRB 210730A: AstroSat CZTI detection
  70. GRB 210730A: Swift-BAT refined analysis
  71. GRB 210730A: Swift-XRT refined Analysis
  72. GRB 210730A: Swift/UVOT Upper Limits
  73. GRB 210724A: Early CAHA 2.2m limit
  74. GRB 210730A: Enhanced Swift-XRT position
  75. GRB 210727A: AstroSat CZTI detection
  76. GRB 210730A: Swift detection of a burst near M82
  77. GRB 210724A: Corrected Swift-XRT enhanced position
  78. Fermi GBM Sub-Threshold Detection of GRB 210725B
  79. GRB 210727A: CALET Gamma-Ray Burst Monitor detection
  80. IPN triangulation of GRB 210727A (short)
  81. Fermi GBM Sub-Threshold Detection of GRB 210726A
  82. GRB 210702A: MeerKAT radio detection
  83. GRB 210726A: Swift-XRT refined Analysis
  84. GRB 210726A: Swift-BAT refined analysis
  85. GRB 210726A: Likely a short burst
  86. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  87. GRB 210727A: AGILE/MCAL detection
  88. GRB 210725A: AbAO optical upper limit
  89. GRB 210724A: Swift/UVOT Upper Limits
  90. GRB 210723A: Swift/UVOT Upper Limits
  91. GRB 210725A: Swift/UVOT Upper Limits
  92. GRB 210725B: Swift/UVOT Upper Limits
  93. GRB 210726A: CAHA 2.2m telescope optical limit
  94. GRB 210726A: Enhanced Swift-XRT position
  95. GRB 210726A: Swift detection of a burst
  96. Swift GRB210726.80: Global MASTER-Net observations report
  97. GRB 210725B: Swift-XRT refined Analysis
  98. GRB 210725A: Fermi GBM detection
  99. GRB 210725A: Swift-XRT refined Analysis
  100. GRB 210725B: Swift-BAT refined analysis

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