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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"

19608 results found.

  1. GRB 230116C: Swift detection of a burst
  2. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  3. GRB 230102A: Fermi GBM Observation
  4. GRB 221231A: 3.6m DOT optical upper limit
  5. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  6. GRB 221231A: Fermi GBM Observation
  7. GRB 221231A: Swift-XRT afterglow detection
  8. GRB 221231A: AKO Upper Limit
  9. GRB 221231A: Swift-XRT observations
  10. GRB 221231A: Swift ToO observations
  11. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  12. GRB 221226A: Fermi GBM detection
  13. IPN triangulation of GRB 221226A
  14. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  15. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  16. GRB 221226B Swift-BAT refined analysis
  17. GRB 221226B: Swift-UVOT Detection
  18. GRB 221226B: Fermi GBM Observation
  19. GRB 221226B: Swift-XRT refined Analysis
  20. GRB 221226B: VLT/X-shooter redshift and host galaxy
  21. GRB 221226B: Enhanced Swift-XRT position
  22. GRB 221226B: Swift detection of a burst
  23. Swift GRB221226.95: Global MASTER-Net observations report
  24. GRB 221215A: Fermi GBM Detection
  25. GRB 221216A: Swift/UVOT Upper Limits
  26. GRB 221216A: Fermi GBM observation
  27. GRB 221216A: Swift-XRT refined Analysis
  28. GRB 221216A: AKO Upper Limit
  29. GRB 221215A: Swift-XRT observations
  30. GRB 221216A: Enhanced Swift-XRT position
  31. Swift GRB 221216A: Global MASTER-Net observations report
  32. GRB 221216A: Zadko observatory - Gingin optical observations
  33. GRB 221216A: Nanshan/NEXT optical upper limits
  34. GRB 221216A: Swift detection of a burst
  35. GRB 221215A: Swift ToO observations
  36. GRB 221215A: Swift/BAT-GUANO arcminute localization
  37. Swift GRB221215.15: Global MASTER-Net observations report
  38. Swift Trigger 1144538 is not a GRB
  39. GRB 221009A: MuSCAT3 observations
  40. GRB 221206B: Fermi GBM observation
  41. GRB 221206B: Swift-XRT observations
  42. GRB 221206B: Detection by GRBAlpha
  43. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  44. GRB 221206B: Swift ToO observations
  45. Swift/BAT trigger #1143281 is not a GRB
  46. Swift GRB221204.45 AKO Upper Limit
  47. Swift GRB221204.45: Global MASTER-Net observations report
  48. GRB 221202A: Swift/UVOT Detection
  49. GRB 221202A: Swift-BAT refined analysis
  50. GRB 221202A: VLT/FORS2 Afterglow Discovery
  51. GRB 221201A: Swift-BAT refined analysis
  52. GRB 221201A: Fermi GBM observation
  53. GRB 221202A: Swift-XRT refined Analysis
  54. GRB 221202A: Enhanced Swift-XRT position
  55. GRB 221202A: MeerLICHT upper limits
  56. GRB 221202A: Swift detection of a burst
  57. Swift GRB221202.84: Global MASTER-Net observations report
  58. GCN: GRB 221201A: Swift/UVOT Upper Limits
  59. GRB 221201A: Swift-XRT refined Analysis
  60. GRB 221201A: Enhanced Swift-XRT position
  61. Swift GRB 221201A: Global MASTER-Net observations report
  62. Konus-Wind detection of GRB 221124A
  63. GRB 221201A: Swift detection of a burst
  64. GRB 221126A: Fermi GBM observation
  65. GRB 221126A: AGILE detection
  66. GRB 221126A: AstroSat CZTI detection
  67. GRB 221126A: Swift/BAT-GUANO detection outside the coded FOV
  68. IPN triangulation of GRB 221124A (long)
  69. GRB 221124A: Swift/BAT-GUANO detection
  70. GRB 221120A: Detection by VZLUSAT-2
  71. GRB 221009A:DAMPE observed a 34.7 GeV photon at 1.36 hour after the GBM trigger
  72. IPN triangulation of GRB 221121A (long)
  73. GRB 221120A: Swift-BAT refined analysis
  74. GRB 221120A: AKO Telescope Upper Limits
  75. GRB221120A: WIRC near-IR imaging of the afterglow candidate
  76. GRB 221120A: Liverpool Telescope Upper Limits
  77. GRB 221120A: Fermi GBM observation
  78. GRB 221120A: Swift-XRT refined Analysis
  79. GRB 221120A: Enhanced Swift-XRT position
  80. GRB221120A: Montarrenti Observatory Upper Limit
  81. GRB 221120A is a short burst
  82. GRB 221120A: Swift/UVOT Upper Limits
  83. GRB 221120A: GIT upper limits on optical afterglow
  84. GRB 221120A: Swift detection of a likely short burst
  85. GRB 221119A: Fermi-LAT detection
  86. GRB 221009A: Japanese VLBI Network observation
  87. GRB 221115B: CALET Gamma-Ray Burst Monitor detection
  88. Correction to GCN 32646 (GRB 221009A (Swift J1913.1+1946): MeerLICHT observations)
  89. GRB 221115B : MeerLICHT upper limits
  90. GRB 221115A: Fermi GBM detection
  91. GRB 221115B: Swift/BAT-GUANO arcminute localization
  92. GRB 221115A: Swift/BAT-GUANO detection
  93. GRB 221110A: GRANDMA observations
  94. GRB 221009A: GRANDMA/Kilonova-Catcher observations
  95. GRB 221110A: Swift/UVOT Detection and Corrected UVOT Position
  96. GRB 221110A: Swift-BAT refined analysis
  97. GRB 221110A: Swift-XRT refined Analysis
  98. GRB 221110A: Enhanced Swift-XRT position
  99. GRB 221110A: LCOGT Optical Afterglow Detection
  100. GRB 221110A: Swift detection of a burst with an optical counterpart

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Download all Circulars as a .tar.gz archive (updated once a day):
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