Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

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"

19663 results found.

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

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov