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 210610B: Fermi GBM detection
  2. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  3. Konus-Wind detection of GRB 210610A
  4. Konus-Wind detection of GRB 210610B
  5. GRB 210610B: AGILE detection
  6. GRB 210610B: GOTO confirmation of afterglow detection
  7. GRB 210610A: Swift-XRT refined Analysis
  8. GRB 210610B: RATIR Optical and NIR Observations
  9. GRB 210610B: Enhanced Swift-XRT position
  10. GRB 210610B: SAO RAS optical observations
  11. GRB 210610A: Swift-BAT refined analysis
  12. GRB 210610A: 1.5m OSN optical observation
  13. GRB210610B: MeerLICHT multi-colour photometry
  14. GRB 210610B: BOOTES-2/TELMA optical observation
  15. Swift GRB 210610B: Global MASTER-Net observations report
  16. GRB 210610B: GIT optical detection
  17. Swift GRB210610.83: Global MASTER-Net OT detection
  18. GRB 210606A: Swift-XRT afterglow detection
  19. GRB 210610B: Swift detection of a burst with bright optical afterglow
  20. GRB 210610A: MITSuME Ishigaki optical observation
  21. GRB210610A: MeerLICHT multi-colour photometry
  22. Swift GRB 210610A: Global MASTER-Net observations report
  23. Swift GRB 210610A: MASTER optical counterpart observation
  24. GRB 210610A: Enhanced Swift-XRT position
  25. GRB 210610A: GIT optical detection
  26. GRB 210610A: Xinglong-2.16m optical afterglow observations
  27. GRB 210610A: MITSuME Akeno optical observation
  28. GRB 210610A: Swift detection of a burst with an optical counterpart
  29. IPN triangulation of GRB 210606B
  30. GRB 210605B: Swift-XRT observations
  31. IPN triangulation of GRB 210605A (short)
  32. GRB 210606A: 1.5m OSN optical upper limit
  33. GECAM Sub-Threshold Detection of new magnetar Swift SGR J1555.2-5402
  34. GRB 210606A: Swift ToO observations
  35. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  36. GRB 210605B: Swift ToO observations
  37. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  38. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  39. Fermi GBM Sub-Threshold Detection of new Swift SGR J1555.2-5402
  40. SGR J1555.2-5402: Swift-BAT refined analysis
  41. Swift J1555.2-5402: Swift XRT refined analysis of the new SGR
  42. NICER discovery of 3.86 s pulsations from a new magnetar: SGR J1555.2-5402
  43. Swift Detection of probable new Swift SGR J1555.2-5402
  44. Swift GRB210603.41: Global MASTER-Net observations report
  45. GRB 210527A: Swift-BAT refined analysis
  46. GRB 210527A: Swift/UVOT Observations
  47. GRB 210527A: GIT optical upper limit
  48. Swift GRB 210527A: Global MASTER-Net observations report
  49. GRB 210527A: Swift-XRT refined Analysis
  50. GRB 210527A: Enhanced Swift-XRT position
  51. GRB 210527A: Swift-XRT observations
  52. GRB 210527A: Swift detection of a burst
  53. IPN triangulation of GRB 210524A
  54. GRB 210520A: Swift-XRT observations
  55. GRB210413B: further Swift-XRT observations
  56. GRB 210520A: Tiled Swift observations
  57. GRB 210520A: Fermi-LAT detection
  58. GRB 210517A: KCT optical upper limit
  59. Konus-Wind detection of GRB 210514A
  60. GRB 210517A: Swift-BAT refined analysis
  61. GRB 210517A: Swift-XRT refined Analysis
  62. GRB 210517A: Swift/UVOT Upper Limits
  63. GRB 210515C: Swift/UVOT Upper Limits
  64. GRB 210517A: AGILE detection
  65. GRB 210514A: CALET Gamma-Ray Burst Monitor detection
  66. GRB 210517A: Enhanced Swift-XRT position
  67. Swift GRB 210517A: Global MASTER-Net observations report
  68. GRB 210517A: Swift detection of a burst
  69. GRB 210515C: LCO Optical Upper Limit
  70. GRB 210504A: LCO Optical Afterglow Detection
  71. GRB 210514A: Swift/UVOT Upper Limits
  72. GRB 210515C: Swift-XRT refined Analysis
  73. Swift GRB210515.83: Global MASTER-Net observations report
  74. GRB 210515C: Swift-BAT refined analysis
  75. GRB 210515C: Swift detection of a burst
  76. GRB 210514A: Swift-BAT refined analysis
  77. Swift GRB210514.71: Global MASTER-Net observations report
  78. GRB 210514A: Swift XRT light curve is fading
  79. GRB 210514A: Swift-XRT refined Analysis
  80. GRB 210514A: Enhanced Swift-XRT position
  81. GRB 210514A: update on the BAT trigger time and burst duration
  82. GRB 210514A: Swift detection of a burst
  83. IPN triangulation of GRB 210427A
  84. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  85. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  86. Swift trigger 1047857 is 4U 1700-377
  87. GRB 210509A: RATIR Optical and NIR Upper Limits
  88. GRB 210509A: Swift/UVOT Upper Limits
  89. GRB 210509A: Swift-XRT refined Analysis
  90. GRB 210509A: Swift-BAT refined analysis
  91. Swift GRB 210509A: Global MASTER-Net observations report
  92. GRB 210509A: Enhanced Swift-XRT position
  93. GRB 210509A: BOOTES-4/MET optical upper limit
  94. GRB 210509A: Swift-XRT observations
  95. GRB 210509A: Swift detection of a burst
  96. GRB 210506A: Swift/BAT-GUANO position retraction
  97. IPN triangulation of GRB 210506A
  98. GRB 210506A: Swift-XRT observations
  99. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  100. GRB 210506A: Swift ToO observations

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