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"

27330 results found.

  1. Fermi trigger No 697396830: Global MASTER-Net observations report
  2. GRB 230205A: Swift/UVOT Upper Limits
  3. GRB 230204B: Fermi GBM detection
  4. Fermi Gamma-ray Burst Monitor triggers due to recent activity of RX J0440.9+4431 (LS V +44 17)
  5. GRB 230205A: LCOGT Optical Upper Limits
  6. GRB 230205A: SVOM/C-GFT optical upper limit
  7. GRB 230205A: OHP/T193 optical observations
  8. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  9. GRB 230204A: Swift-BAT refined analysis
  10. GRB 230205A: Swift-XRT refined Analysis
  11. GRB 230205A: BOOTES-5/JGT early optical upper limit
  12. GRB 230204B: Detection by GRBAlpha
  13. GRB 230205A: Swift detection of a burst
  14. GRB 230204B: GIT discovery of the likely optical afterglow
  15. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  16. GRB 230204A: Swift/UVOT Upper Limits
  17. GRB 230204A: Swift-XRT refined Analysis
  18. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  19. Fermi trigger No 697208885: Global MASTER-Net observations report
  20. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  21. GRB 230201B: TURBO Optical Upper Limits
  22. Fermi Gamma-ray Burst Monitor trigger 230203275 / 697098930 is not a GRB
  23. Fermi trigger No 697098930: Global MASTER-Net observations report
  24. GRB 221216A: Swift-BAT refined analysis
  25. IceCube Alert 230201.26: Global MASTER-Net observations report
  26. Fermi GRB 230201B: Global MASTER-Net observations report
  27. GRB 230201B: Fermi GBM Final Real-time Localization
  28. Fermi GRB 230201A: Global MASTER-Net observations report
  29. GRB 230201A: Fermi GBM Final Real-time Localization
  30. GRB 230130A: Fermi GBM Final Real-time Localization
  31. GRB 230129A: Fermi GBM Final Real-time Localization
  32. GRB 230128A: Fermi GBM Final Real-time Localization
  33. ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
  34. GRB 230126A: Fermi GBM Final Real-time Localization
  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 230114B: Detection by VZLUSAT-2
  39. GRB 230123A: LCOGT Optical Upper Limits
  40. Fermi GRB 230124A: Global MASTER-Net observations report
  41. GRB 230124A: Fermi GBM Final Real-time Localization
  42. GRB 230123A: Swift-BAT refined analysis
  43. GRB 230122A: Swift/BAT-GUANO detection
  44. GRB 230123A: Swift/UVOT Upper Limits
  45. GRB 230123A: Swift-XRT refined Analysis
  46. GRB 230123A: Zadko observatory - Gingin optical observations
  47. GRB 230123A: Swift detection of a burst
  48. IceCube Alert 230122.16: Global MASTER-Net observations report
  49. GRB 230116B: Fermi GBM observation
  50. Trigger 1150107: Swift detection of LS V +44 17
  51. IPN triangulation of GRB 230116B (short)
  52. GRB 230119A: CALET Gamma-Ray Burst Monitor detection
  53. GRB 230119A: Fermi GBM Final Real-time Localization
  54. Fermi GRB 230118A: Global MASTER-Net observations report
  55. GRB 230118A: Fermi GBM Final Real-time Localization
  56. GRB 230116D: Swift-BAT refined analysis
  57. GRB 230116C: Swift-BAT refined analysis
  58. GRB 230116D: LCOGT Optical Upper Limit
  59. Fermi trigger No 695569700: Global MASTER-Net observations report
  60. GRB 230116D: Swift-XRT refined Analysis
  61. Fermi GRB 230117A: Global MASTER-Net observations report
  62. GRB 230117A: Fermi GBM Final Real-time Localization
  63. GRB 230116D: GIT optical follow-up
  64. GRB 230116D: Nanshan/NEXT optical afterglow detection
  65. GRB 230116D: Swift detection of a burst
  66. Swift GRB230116.88: Global MASTER-Net observations report
  67. GRB 230116C: Swift detection of a burst
  68. GRB 230116B: Fermi GBM Final Real-time Localization
  69. GRB 230116A: Fermi GBM Final Real-time Localization
  70. GRB 230114A: Fermi GBM Final Real-time Localization
  71. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  72. GRB 230111A: Fermi GBM Observation
  73. Fermi GRB 230112A: Global MASTER-Net observations report
  74. IceCube Alert 230112.28: Global MASTER-Net observations report
  75. GRB 230112A: Fermi GBM Final Real-time Localization
  76. GRB 230111A: Fermi GBM Final Real-time Localization
  77. Fermi trigger No 695057654: Global MASTER-Net observations report
  78. GRB 230102A: Fermi GBM Observation
  79. Fermi Gamma-ray Burst Monitor trigger 694043024/221229905 is not a GRB
  80. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  81. GRB 221231A: Fermi GBM Observation
  82. GRB 221230A: CALET Gamma-Ray Burst Monitor detection
  83. Fermi Gamma-ray Burst Monitor trigger 694259491/230101411 is not a GRB
  84. Fermi Gamma-ray Burst Monitor trigger 694302022/230101903 is not a GRB
  85. Fermi trigger No 694259491: Global MASTER-Net observations report
  86. GRB 230102A: Fermi GBM Final Real-time Localization
  87. GRB 221231A: AKO Upper Limit
  88. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  89. Fermi trigger No 694232203: Global MASTER-Net observations report
  90. GRB 230101A: Fermi GBM Final Real-time Localization
  91. GRB 221231A: Fermi GBM Final Real-time Localization
  92. GRB 221226A: Fermi GBM detection
  93. IPN triangulation of GRB 221226A
  94. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  95. GRB 221226B: LCOGT Optical Upper Limits
  96. GRB 221228A: Fermi GBM Final Real-time Localization
  97. GRB 221226B Swift-BAT refined analysis
  98. GRB 221226B: Swift-UVOT Detection
  99. GRB 221226B: Fermi GBM Observation
  100. GRB 221226B: Swift-XRT refined Analysis

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