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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"

19666 results found.

  1. IPN triangulation of GRB 230209B
  2. GRB 230204B: CALET Gamma-Ray Burst Monitor detection
  3. GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
  4. Swift Trigger 1153670 is probably not a GRB
  5. GRB 221009A: Continued Swift Observations
  6. GRB 230207B: Detection by GRBAlpha
  7. GRB 230207B: Swift/BAT-GUANO detection outside the coded FOV
  8. ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
  9. GRB 230204B: Swift/UVOT Upper Limits
  10. GRB 230205A: Swift/UVOT Upper Limits
  11. GRB 230204B: Fermi GBM detection
  12. GRB 230204B: Swift-XRT afterglow detection
  13. GRB 230205A: SVOM/C-GFT optical upper limit
  14. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  15. GRB 230204A: Swift-BAT refined analysis
  16. GRB 230205A: Swift-XRT refined Analysis
  17. GRB 230204B: Swift ToO observations
  18. GRB 230205A: Enhanced Swift-XRT position
  19. GRB 230205A: BOOTES-5/JGT early optical upper limit
  20. GRB 230204B: Detection by GRBAlpha
  21. GRB 230204B: AGILE detection
  22. GRB 230205A: Swift detection of a burst
  23. GRB 230204B: GIT discovery of the likely optical afterglow
  24. GRB 230204B: AstroSat CZTI detection
  25. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  26. GRB 230204A: Swift/UVOT Upper Limits
  27. GRB 230204A: Swift-XRT refined Analysis
  28. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  29. GRB 230204A: Enhanced Swift-XRT position
  30. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  31. GRB 221216A: Swift-BAT refined analysis
  32. AT2023avj: X-ray Detection with Swift/XRT
  33. Swift-XRT observations of NuEm-230125A
  34. Trigger 1150965: Swift detection of LS V +44 17
  35. GRB 230124A: Fermi GBM Observation
  36. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  37. GRB 230123A: Swift-BAT refined analysis
  38. GRB 230122A: Swift/BAT-GUANO detection
  39. GRB 230123A: Swift/UVOT Upper Limits
  40. GRB 230123A: Swift-XRT refined Analysis
  41. GRB 230123A: Enhanced Swift-XRT position
  42. GRB 230123A: Zadko observatory - Gingin optical observations
  43. GRB 230116C: Swift-XRT observations
  44. GRB 230123A: Swift detection of a burst
  45. Trigger 1150107: Swift detection of LS V +44 17
  46. GRB 230116D: 3.6m DOT optical upper limit
  47. GRB 230116D: Swift-BAT refined analysis
  48. GRB 230116C: Swift-BAT refined analysis
  49. GRB 230116D: Swift-XRT refined Analysis
  50. GRB 230116D: GIT optical follow-up
  51. GRB 230116D: Enhanced Swift-XRT position
  52. GRB 230116D: Nanshan/NEXT optical afterglow detection
  53. GRB 230116D: Swift detection of a burst
  54. Swift GRB230116.88: Global MASTER-Net observations report
  55. GRB 230116C: Swift detection of a burst
  56. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  57. GRB 230102A: Fermi GBM Observation
  58. GRB 221231A: 3.6m DOT optical upper limit
  59. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  60. GRB 221231A: Fermi GBM Observation
  61. GRB 221231A: Swift-XRT afterglow detection
  62. GRB 221231A: AKO Upper Limit
  63. GRB 221231A: Swift-XRT observations
  64. GRB 221231A: Swift ToO observations
  65. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  66. GRB 221226A: Fermi GBM detection
  67. IPN triangulation of GRB 221226A
  68. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  69. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  70. GRB 221226B Swift-BAT refined analysis
  71. GRB 221226B: Swift-UVOT Detection
  72. GRB 221226B: Fermi GBM Observation
  73. GRB 221226B: Swift-XRT refined Analysis
  74. GRB 221226B: VLT/X-shooter redshift and host galaxy
  75. GRB 221226B: Enhanced Swift-XRT position
  76. GRB 221226B: Swift detection of a burst
  77. Swift GRB221226.95: Global MASTER-Net observations report
  78. GRB 221215A: Fermi GBM Detection
  79. GRB 221216A: Swift/UVOT Upper Limits
  80. GRB 221216A: Fermi GBM observation
  81. GRB 221216A: Swift-XRT refined Analysis
  82. GRB 221216A: AKO Upper Limit
  83. GRB 221215A: Swift-XRT observations
  84. GRB 221216A: Enhanced Swift-XRT position
  85. Swift GRB 221216A: Global MASTER-Net observations report
  86. GRB 221216A: Zadko observatory - Gingin optical observations
  87. GRB 221216A: Nanshan/NEXT optical upper limits
  88. GRB 221216A: Swift detection of a burst
  89. GRB 221215A: Swift ToO observations
  90. GRB 221215A: Swift/BAT-GUANO arcminute localization
  91. Swift GRB221215.15: Global MASTER-Net observations report
  92. Swift Trigger 1144538 is not a GRB
  93. GRB 221009A: MuSCAT3 observations
  94. GRB 221206B: Fermi GBM observation
  95. GRB 221206B: Swift-XRT observations
  96. GRB 221206B: Detection by GRBAlpha
  97. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  98. GRB 221206B: Swift ToO observations
  99. Swift/BAT trigger #1143281 is not a GRB
  100. Swift GRB221204.45 AKO Upper Limit

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