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"

36402 results found.

  1. GRB 230205A: OHP/T193 optical observations
  2. GRB 230204B: VLT/X-shooter redshift
  3. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  4. GRB 230204A: Swift-BAT refined analysis
  5. GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
  6. GRB 230205A: Swift-XRT refined Analysis
  7. GRB 230204B: Swift ToO observations
  8. GRB 230205A: Enhanced Swift-XRT position
  9. GRB 230205A: BOOTES-5/JGT early optical upper limit
  10. GRB 230204B: Detection by GRBAlpha
  11. GRB 230204B: AGILE detection
  12. GRB 230205A: Swift detection of a burst
  13. GRB 230204B: GIT discovery of the likely optical afterglow
  14. GRB 230204B: AstroSat CZTI detection
  15. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  16. GRB 230204A: Swift/UVOT Upper Limits
  17. GRB 230204B: MAXI/GSC detection
  18. GRB 230204A: Swift-XRT refined Analysis
  19. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  20. GRB 230204A: Enhanced Swift-XRT position
  21. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  22. GRB 230201B: TURBO Optical Upper Limits
  23. Fermi Gamma-ray Burst Monitor trigger 230203275 / 697098930 is not a GRB
  24. GRB 221216A: Swift-BAT refined analysis
  25. Fermi GRB 230201B: Global MASTER-Net observations report
  26. GRB 230201B: Fermi GBM Final Real-time Localization
  27. GRB 230126A: Detection by VZLUSAT-2
  28. Fermi GRB 230201A: Global MASTER-Net observations report
  29. GRB 221009A: radio afterglow detection with the EVN
  30. GRB 230201A: Fermi GBM Final Real-time Localization
  31. ZTF23aaarlti/AT2023avj: Assy continued optical observations
  32. ZTF23aabmzlp/AT2023azs: Mondy and AbAO optical observations
  33. AT2023avj: X-ray Detection with Swift/XRT
  34. GRB 230129A: AstroSat CZTI detection
  35. GRB 230128A: AstroSat CZTI detection
  36. GRB 230130A: Fermi GBM Final Real-time Localization
  37. GRB 230129A: Fermi GBM Final Real-time Localization
  38. GRB 230128A: Fermi GBM Final Real-time Localization
  39. AT2023avj ZTF Candidate: Assy optical observations
  40. GRB 230126A: Fermi GBM Final Real-time Localization
  41. GRB 230124A: Fermi GBM Observation
  42. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  43. GRB 230114B: Detection by VZLUSAT-2
  44. GRB 230123A: LCOGT Optical Upper Limits
  45. Fermi GRB 230124A: Global MASTER-Net observations report
  46. GRB 230124A: Fermi GBM Final Real-time Localization
  47. GRB 230123A: Swift-BAT refined analysis
  48. GRB 230122A: Swift/BAT-GUANO detection
  49. GRB 230123A: Swift/UVOT Upper Limits
  50. GRB 230123A: Swift-XRT refined Analysis
  51. GRB 230123A: Enhanced Swift-XRT position
  52. GRB 230123A: Zadko observatory - Gingin optical observations
  53. GRB 230116C: Swift-XRT observations
  54. GRB 230123A: Swift detection of a burst
  55. GRB 230116B: Fermi GBM observation
  56. GRB 230120A: AstroSat CZTI detection
  57. IPN triangulation of GRB 230116B (short)
  58. GRB 230119A: CALET Gamma-Ray Burst Monitor detection
  59. GRB 230116D: 3.6m DOT optical upper limit
  60. GRB 230119A: Fermi GBM Final Real-time Localization
  61. Fermi GRB 230118A: Global MASTER-Net observations report
  62. GRB 230118A: Fermi GBM Final Real-time Localization
  63. GRB 230116D: Swift-BAT refined analysis
  64. GRB 230116C: Swift-BAT refined analysis
  65. GRB 230116D: SAO RAS further observations
  66. GRB 230116D: SAO RAS photometry
  67. GRB 230116D: KGO RC-25 optical observations
  68. GRB 230116D: Sintez-Newton/CrAO optical observations
  69. GRB 230116D: LCOGT Optical Upper Limit
  70. GRB 230116D: SAO RAS redshift
  71. GRB 230116D: Swift-XRT refined Analysis
  72. Fermi GRB 230117A: Global MASTER-Net observations report
  73. GRB 230117A: Fermi GBM Final Real-time Localization
  74. GRB 230116D: GIT optical follow-up
  75. GRB 230116D: GIT optical follow-up
  76. GRB 230116D: Enhanced Swift-XRT position
  77. GRB 230116D: SAO RAS observations of OT brightening
  78. GRB 230116D: Sintez-Newton/CrAO optical afterglow detection
  79. GRB 230116D: Nanshan/NEXT optical afterglow detection
  80. GRB 230116D: Swift detection of a burst
  81. GRB 230116C: Swift detection of a burst
  82. GRB 230116B: Fermi GBM Final Real-time Localization
  83. GRB 230116A: Fermi GBM Final Real-time Localization
  84. GRB 230114A: Detection by VZLUSAT-2
  85. GRB 230114A: Fermi GBM Final Real-time Localization
  86. GRB 230111A: Fermi GBM Observation
  87. Fermi GRB 230112A: Global MASTER-Net observations report
  88. GRB 230112A: Fermi GBM Final Real-time Localization
  89. GRB 230111A: MAXI/GSC detection
  90. GRB 230111A: Fermi GBM Final Real-time Localization
  91. GRB 230106: AstroSat LAXPC detection
  92. GRB 230102A: Fermi GBM Observation
  93. Fermi Gamma-ray Burst Monitor trigger 694043024/221229905 is not a GRB
  94. GRB 221231A: 3.6m DOT optical upper limit
  95. GRB 230104A: AGILE/MCAL detection of a burst
  96. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  97. GRB 221231A: Fermi GBM Observation
  98. GRB 221230A: CALET Gamma-Ray Burst Monitor detection
  99. Fermi Gamma-ray Burst Monitor trigger 694259491/230101411 is not a GRB
  100. GRB 230102A: Detection by GRBAlpha

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