Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. 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"

19670 results found.

  1. GRB 211225B: Swift detection of a burst
  2. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  3. GRB 211223C: Swift-BAT refined analysis
  4. GRB 211223C: BOOTES-4/MET optical upper limit
  5. Swift GRB 211223C: Global MASTER-Net observations report
  6. Fermi GBM Sub-Threshold Detection of GRB 211221A
  7. Fermi GBM Sub-Threshold Detection of GRB 211207A
  8. GRB 211221A: Swift-BAT refined analysis
  9. GRB 211223C: Swift detection of a burst
  10. GRB 211219A: AstroSat CZTI detection
  11. GRB 211221A: Swift-XRT refined Analysis
  12. GRB 211221A: BOOTES-4/MET optical upper limit
  13. GRB 211221A: MeerLICHT optical limits
  14. GRB 211221A: Enhanced Swift-XRT position
  15. Swift GRB 211221A: Global MASTER-Net observations report
  16. GRB 211221A: Swift detection of a burst
  17. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  18. GRB 211216A: Fermi GBM observation
  19. GRB 211216A: Swift/BAT-GUANO detection outside the coded FOV
  20. GRB 211211A: Insight-HXMT/HE detection
  21. GRB 211211A: HCT and GIT optical follow up observations
  22. GRB 211211A: CALET Gamma-Ray Burst Monitor detection
  23. GRB 211211A: Swift/UVOT detection
  24. GRB 211211A: NOT optical spectroscopy
  25. Swift GRB 211211A: Global MASTER-Net observations report
  26. GRB 211211A: LCO Optical Observations
  27. GRB 211211A: Nanshan/NEXT optical observations
  28. GRB 211211A: Swift-XRT refined Analysis
  29. GRB 211211A: Fermi GBM observation
  30. GRB 211211A: Swift-BAT refined analysis
  31. GRB 211211A: Enhanced Swift-XRT position
  32. GRB 211207A: Swift/UVOT Detection
  33. GRB 211211A: KAIT Optical Afterglow Candidate
  34. GRB 211211A: Swift detection of a bright burst
  35. GRB 211207A: Swift-BAT refined analysis
  36. GRB 211204C: Fermi GBM detection
  37. GRB 211207A: Swift-XRT refined Analysis
  38. GRB 211207A: Enhanced Swift-XRT position
  39. Swift GRB 211207A: Global MASTER-Net observations report
  40. GRB 211207A: Swift detection of a burst with an optical counterpart
  41. GRB 211206A: AstroSat CZTI detection
  42. GRB 211204C: AstroSat CZTI detection
  43. IPN triangulation of GRB 211204C
  44. GRB 211206A: Swift/BAT-GUANO detection outside the coded FOV
  45. GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV
  46. GRB 211124A: Fermi GBM Observation
  47. Swift Trigger 1086826 (possible GRB 211203A) is likely not an astrophysical event
  48. Swift GRB 211203A: Global MASTER-Net observations report
  49. Fermi GBM Upper limits for GRB 211203A
  50. GRB 211203A: Swift detection of a burst
  51. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  52. GRB 211106A: GECAM detection
  53. GRB 211129A: Swift-BAT refined analysis
  54. GRB 211129A: Swift-XRT refined Analysis
  55. GRB 211129A: Swift/UVOT Upper Limits
  56. GRB 211129A: Fermi GBM observation
  57. Swift GRB 211129A: Global MASTER-Net observations report
  58. GRB 211129A: Nanshan/NEXT optical upper limit
  59. GRB 211129A: Enhanced Swift-XRT position
  60. IPN triangulation of GRB 211118A
  61. GRB 211129A: MITSuME Akeno optical upper limits
  62. GRB 211129A: Swift detection of a burst
  63. GRB 211120548: Fermi GBM observation
  64. Chandra observations of GRB 210905A
  65. GRB 211118A: Fermi GBM detection
  66. IPN triangulation of GRB 211124A (short)
  67. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  68. Trigger_21473: Tiled Swift observations
  69. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  70. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  71. GRB 211118A: AstroSat CZTI detection
  72. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  73. Fermi trigger No 658971499: Global MASTER-Net observations report
  74. Konus-Wind detection of GRB 211107B
  75. GRB 211106A: Swift/UVOT upper limits
  76. IPN triangulation of GRB 211106A (short)
  77. GRB 211107B: Swift-XRT afterglow detection
  78. GRB 211106A: Swift-XRT afterglow detection
  79. GRB 211107B: Swift-XRT observations
  80. MeerLICHT follow-up of GRB 211106A
  81. GRB 211107B: Swift ToO observations
  82. GRB 211107B: Swift/BAT detection
  83. Fermi GBM Sub-Threshold Detection of GRB 211106A
  84. Konus-Wind detection of GRB 211106A
  85. GRB 211106A: Swift-XRT observations
  86. GRB 211106A: Swift ToO observations
  87. GRB 211106A: Swift/BAT-GUANO candidate arcminute localization of a short burst
  88. GRB 211105A: Swift/BAT-GUANO detection outside the coded FOV
  89. Swift Trigger 1082569 is probably not a GRB
  90. GRB 211024A: MITSuME Akeno optical observation
  91. GRB 211023B: MITSuME Akeno optical upper limits
  92. GRB 211024A: 1.3m DFOT observations
  93. IPN triangulation of GRB 211022A
  94. AMON NuEm-211020A: No Candidate Counterparts from Swift-XRT follow up observations
  95. GRB 211024A: Swift-XRT source 4 is not an afterglow.
  96. GRB 211024A: Possible afterglow candidate from GIT
  97. GRB 211024A: Swift-XRT observations
  98. GRB 211024A: Fermi GBM detection
  99. GRB 211018A: Swift-XRT observations
  100. GRB 211025A: Optical Afterglow Detection

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