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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"

21525 results found.

  1. GRB 230116C: Swift-BAT refined analysis
  2. GRB 230116D: SAO RAS photometry
  3. GRB 230116D: LCOGT Optical Upper Limit
  4. GRB 230116D: Swift-XRT refined Analysis
  5. GRB 230116D: GIT optical follow-up
  6. GRB 230116D: Enhanced Swift-XRT position
  7. GRB 230116D: SAO RAS observations of OT brightening
  8. GRB 230116D: Sintez-Newton/CrAO optical afterglow detection
  9. GRB 230116D: Nanshan/NEXT optical afterglow detection
  10. GRB 230116D: Swift detection of a burst
  11. Swift GRB230116.88: Global MASTER-Net observations report
  12. GRB 230116C: Swift detection of a burst
  13. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  14. GRB 230102A: Fermi GBM Observation
  15. GRB 221231A: 3.6m DOT optical upper limit
  16. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  17. GRB 221231A: Fermi GBM Observation
  18. GRB 221231A: Swift-XRT afterglow detection
  19. GRB 221231A: AKO Upper Limit
  20. GRB 221231A: Swift-XRT observations
  21. GRB 221231A: Swift ToO observations
  22. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  23. GRB 221226A: Fermi GBM detection
  24. IPN triangulation of GRB 221226A
  25. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  26. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  27. GRB 221226B: LCOGT Optical Upper Limits
  28. GRB 221226B Swift-BAT refined analysis
  29. GRB 221226B: Swift-UVOT Detection
  30. GRB 221226B: Fermi GBM Observation
  31. GRB 221226B: Swift-XRT refined Analysis
  32. GRB 221226B: VLT/X-shooter redshift and host galaxy
  33. GRB 221226B: Enhanced Swift-XRT position
  34. GRB 221226B: Swift detection of a burst
  35. Swift GRB221226.95: Global MASTER-Net observations report
  36. GRB 221215A: Fermi GBM Detection
  37. GRB 221216A: Swift/UVOT Upper Limits
  38. GRB 221216A: Fermi GBM observation
  39. GRB 221216A: Swift-XRT refined Analysis
  40. GRB 221216A: AKO Upper Limit
  41. GRB 221215A: Swift-XRT observations
  42. GRB 221216A: Enhanced Swift-XRT position
  43. Swift GRB 221216A: Global MASTER-Net observations report
  44. GRB 221216A: Zadko observatory - Gingin optical observations
  45. GRB 221216A: Nanshan/NEXT optical upper limits
  46. GRB 221216A: Swift detection of a burst
  47. GRB 221215A: Swift ToO observations
  48. GRB 221215A: Swift/BAT-GUANO arcminute localization
  49. Swift GRB221215.15: Global MASTER-Net observations report
  50. Swift Trigger 1144538 is not a GRB
  51. GRB 221009A: MuSCAT3 observations
  52. GRB 221206B: Fermi GBM observation
  53. GRB 221206B: Swift-XRT observations
  54. GRB 221206B: Detection by GRBAlpha
  55. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  56. GRB 221206B: Swift ToO observations
  57. Swift/BAT trigger #1143281 is not a GRB
  58. Swift GRB221204.45 AKO Upper Limit
  59. Swift GRB221204.45: Global MASTER-Net observations report
  60. GRB 221202A: Swift/UVOT Detection
  61. GRB 221202A: Swift-BAT refined analysis
  62. GRB 221202A: VLT/FORS2 Afterglow Discovery
  63. GRB 221201A: Swift-BAT refined analysis
  64. GRB 221201A: Fermi GBM observation
  65. GRB 221202A: Swift-XRT refined Analysis
  66. GRB 221202A: LCOGT Optical Upper Limits
  67. GRB 221202A: Enhanced Swift-XRT position
  68. GRB 221202A: MeerLICHT upper limits
  69. GRB 221202A: Swift detection of a burst
  70. Swift GRB221202.84: Global MASTER-Net observations report
  71. GCN: GRB 221201A: Swift/UVOT Upper Limits
  72. GRB 221201A: Swift-XRT refined Analysis
  73. GRB 221201A: Enhanced Swift-XRT position
  74. Swift GRB 221201A: Global MASTER-Net observations report
  75. Konus-Wind detection of GRB 221124A
  76. GRB 221201A: Swift detection of a burst
  77. GRB 221126A: Fermi GBM observation
  78. GRB 221126A: AGILE detection
  79. GRB 221126A: AstroSat CZTI detection
  80. GRB 221126A: Swift/BAT-GUANO detection outside the coded FOV
  81. IPN triangulation of GRB 221124A (long)
  82. GRB 221124A: Swift/BAT-GUANO detection
  83. GRB 221120A: Detection by VZLUSAT-2
  84. GRB 221120A: TURBO Optical Upper Limit
  85. GRB 221120A: VIRT Optical Upper Limit
  86. GRB 221009A：DAMPE observed a 34.7 GeV photon at 1.36 hour after the GBM trigger
  87. IPN triangulation of GRB 221121A (long)
  88. GRB 221120A: Swift-BAT refined analysis
  89. GRB 221120A: AKO Telescope Upper Limits
  90. GRB221120A: WIRC near-IR imaging of the afterglow candidate
  91. GRB 221120A: Liverpool Telescope Upper Limits
  92. GRB 221120A: Archival PS1 Imaging of Faint Source near XRT position
  93. GRB 221120A: Fermi GBM observation
  94. GRB 221120A: Swift-XRT refined Analysis
  95. GRB 221120A: Enhanced Swift-XRT position
  96. GRB221120A: Montarrenti Observatory Upper Limit
  97. GRB 221120A is a short burst
  98. GRB 221120A: Swift/UVOT Upper Limits
  99. GRB 221120A: LDT Optical Afterglow Candidate
  100. GRB 221120A: GIT upper limits on optical afterglow

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