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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"

35949 results found.

  1. GRB 221231A: 3.6m DOT optical upper limit
  2. GRB 230104A: AGILE/MCAL detection of a burst
  3. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  4. GRB 221231A: Fermi GBM Observation
  5. GRB 221230A: CALET Gamma-Ray Burst Monitor detection
  6. Fermi Gamma-ray Burst Monitor trigger 694259491/230101411 is not a GRB
  7. GRB 230102A: Detection by GRBAlpha
  8. Fermi Gamma-ray Burst Monitor trigger 694302022/230101903 is not a GRB
  9. GRB 230101A: AstroSat CZTI detection
  10. GRB 221231A: Swift-XRT afterglow detection
  11. GRB 230102A: AGILE/MCAL detection
  12. GRB 230102A: Fermi GBM Final Real-time Localization
  13. GRB 221231A: AKO Upper Limit
  14. GRB 221231A: Swift-XRT observations
  15. GRB 221231A: Swift ToO observations
  16. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  17. GRB 230101A: Fermi GBM Final Real-time Localization
  18. GRB 221231A: Fermi GBM Final Real-time Localization
  19. GRB 221226A: Fermi GBM detection
  20. IPN triangulation of GRB 221226A
  21. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  22. GRB 221226B: LCOGT Optical Upper Limits
  23. GRB 221228A: Fermi GBM Final Real-time Localization
  24. GRB 221226B Swift-BAT refined analysis
  25. GRB 221226B: Swift-UVOT Detection
  26. GRB 221226A: AGILE detection
  27. GRB 221226B: Fermi GBM Observation
  28. GRB 221226B: Swift-XRT refined Analysis
  29. GRB 221226B: VLT/X-shooter redshift and host galaxy
  30. GRB 221226B: Enhanced Swift-XRT position
  31. GRB 221226B: Swift detection of a burst
  32. GRB 221226B: Fermi GBM Final Real-time Localization
  33. Fermi GRB 221226A: Global MASTER-Net observations report
  34. GRB 221226A: Fermi GBM Final Real-time Localization
  35. Fermi GRB 221223A: Global MASTER-Net observations report
  36. GRB 221223A: Fermi GBM Final Real-time Localization
  37. GRB 221221A: AGILE detection
  38. Fermi GRB 221221A: Global MASTER-Net observations report
  39. GRB 221221A: Fermi GBM Final Real-time Localization
  40. GRB 221218A: 3.6m DOT optical upper limit
  41. GRB 221216A: Detection by VZLUSAT-2
  42. GRB 221218A: MITSuME Akeno optical upper limits
  43. GRB 221218A: BOOTES-4/MET and OSN optical upper limits
  44. GRB 221218A: KAIT Optical Upper Limit
  45. GRB 221215A: Fermi GBM Detection
  46. GRB 221218A: a long GRB detected by INTEGRAL
  47. GRB 221216A: Swift/UVOT Upper Limits
  48. GRB 221216A: Fermi GBM observation
  49. GRB 221216A: Swift-XRT refined Analysis
  50. GRB 221216A: AKO Upper Limit
  51. GRB 221215A: Swift-XRT observations
  52. GRB 221216A: Enhanced Swift-XRT position
  53. Swift GRB 221216A: Global MASTER-Net observations report
  54. GRB 221216A: Zadko observatory - Gingin optical observations
  55. GRB 221216A: Nanshan/NEXT optical upper limits
  56. GRB 221216A: Swift detection of a burst
  57. GRB 221216A: Fermi GBM Final Real-time Localization
  58. GRB 221215A: Swift ToO observations
  59. GRB 221215A: Swift/BAT-GUANO arcminute localization
  60. Konus-Wind detection of GRB 221209A
  61. Fermi GRB 221215B: Global MASTER-Net observations report
  62. IPN triangulation of GRB 221209A (long)
  63. GRB 221215B: Fermi GBM Final Real-time Localization
  64. Fermi Gamma-ray Burst Monitor trigger 692760884/221215066 is not a GRB
  65. GRB 221215A: Fermi GBM Final Real-time Localization
  66. Swift Trigger 1144538 is not a GRB
  67. GRB 221209A: CALET Gamma-Ray Burst Monitor detection
  68. GRB 221212A: Fermi GBM Final Real-time Localization
  69. Fermi GRB 221211A: Global MASTER-Net observations report
  70. GRB 221208A: AstroSat CZTI detection
  71. GRB 221211A: Fermi GBM Final Real-time Localization
  72. GRB 221009A: MuSCAT3 observations
  73. GRB 221209A: AstroSat CZTI detection
  74. GRB 221210A: Fermi GBM Final Real-time Localization
  75. GRB 221209B: Fermi GBM Final Real-time Localization
  76. GRB 221209A: Fermi GBM observation
  77. GRB 221203C: AstroSat CZTI detection
  78. GRB 221209A: BALROG localization (Fermi Trigger 692257829 / GRB 221209243)
  79. GRB 221209A: Fermi GBM Final Real-time Localization
  80. GRB 221206B: Fermi GBM observation
  81. GRB 221206B: Swift-XRT observations
  82. GRB 221206B: Detection by GRBAlpha
  83. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  84. GRB 221206B: Swift ToO observations
  85. Swift/BAT trigger #1143281 is not a GRB
  86. GRB 221206C: Fermi GBM Final Real-time Localization
  87. GRB 221206B: Fermi GBM Final Real-time Localization
  88. GRB 221206A: Fermi GBM Final Real-time Localization
  89. GRB 221205A: Fermi GBM Final Real-time Localization
  90. GRB 221202B: Detection by VZLUSAT-2
  91. GRB 221203B: Fermi GBM Final Real-time Localization
  92. GRB 221202A: Swift/UVOT Detection
  93. GRB 221202A: Swift-BAT refined analysis
  94. GRB 221202A: VLT/FORS2 Afterglow Discovery
  95. GRB 221201A: Swift-BAT refined analysis
  96. GRB 221203A: Fermi GBM Final Real-time Localization
  97. GRB 221201A: Fermi GBM observation
  98. GRB 221202A: Swift-XRT refined Analysis
  99. GRB 221202A: LCOGT Optical Upper Limits
  100. GRB 221202A: Enhanced Swift-XRT position

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