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"

27963 results found.

  1. Swift GRB210910.42: Global MASTER-Net observations report
  2. Konus-Wind detection of the second intermediate flare from SGR 1935+2154
  3. IPN triangulation of a bright burst from SGR 1935+2154
  4. GRB 210826A: further Swift-XRT observations
  5. GRB 210909B: GECAM detection
  6. Swift detection of a burst from SGR Swift J1555.2-5402
  7. GRB 210909A: Fermi GBM Final Real-time Localization
  8. GRB 210905A: Swift/UVOT Upper Limits
  9. GRB 210905A: ATCA detection
  10. GRB 210905A: ALMA detection
  11. GRB 210905A: AstroSat CZTI detection
  12. GRB 210905A, GROND observations
  13. Konus-Wind detection of GRB 210905A
  14. Fermi GBM Sub-Threshold Detection of GRB 210905A
  15. GRB 210905A: Swift-XRT refined Analysis
  16. GRB 210827B: GECAM detection
  17. GRB 210905A: DECam Detection
  18. GRB 210905A: REM NIR afterglow detection
  19. GRB 210905A: VLT/X-shooter spectroscopic redshift
  20. GRB 210905A: Continued LCO Optical Observations
  21. GRB 210905A: LCO Optical Detection
  22. GRB 210905A: Enhanced Swift-XRT position
  23. GRB 210901A: Swift/UVOT Upper Limits
  24. Swift GRB 210905A: Global MASTER-Net observations report
  25. GRB 210905A: Swift detection of a burst
  26. GRB 210904A: Fermi GBM Final Real-time Localization
  27. Swift GRB210903.59: Global MASTER-Net observations report
  28. Swift GRB210903.58: Global MASTER-Net observations report
  29. Swift GRB210903.58: Global MASTER-Net observations report
  30. GRB 210903C: Fermi GBM Final Real-time Localization
  31. GRB 210901A: GROND observations
  32. GRB 210903B: Fermi GBM Final Localization
  33. Fermi GBM observation of a burst from SGR J1555.2-5402
  34. GRB 210903A: Fermi GBM Final Real-time Localization
  35. GRB 210901A: Swift-XRT refined Analysis
  36. GRB 210901A: Swift-BAT refined analysis
  37. GRB 210901A: Enhanced Swift-XRT position
  38. GRB 210901A: LCO Optical Upper Limit
  39. Swift GRB 210901A: Global MASTER-Net observations report
  40. GRB 210901A: Swift detection of a burst
  41. GRB 210827A: further Swift-XRT observations
  42. GRB 210822A: CALET Gamma-Ray Burst Monitor detection
  43. GRB 210827A: Swift/UVOT Upper Limits
  44. GRB 210827A: BOOTES-5/JGT optical upper limit
  45. GRB 210827A: Fermi GBM Observation
  46. GRB 210826A: AstroSat CZTI detection
  47. GRB 210827A: Swift-XRT observations
  48. GRB 210827A: Swift ToO observations
  49. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  50. GRB 210820A: CAHA 2.2m Optical Detection
  51. GRB 210824A: Swift/UVOT Upper Limits
  52. GRB 210826A: Swift/UVOT Upper Limits
  53. POLAR detection of a SGR-like burst
  54. GRB 210827B: Fermi GBM Final Real-time Localization
  55. GRB 210826A: Swift-XRT observations
  56. GRB 210827A: Fermi GBM Final Real-time Localization
  57. GRB 210822A: CAHA 2.2m observations
  58. GRB 210824A: Swift-BAT refined analysis
  59. GRB 210826A: Fermi-LAT detection
  60. GRB 210826A: Tiled Swift observations
  61. GRB 210826A: Fermi GBM Final Real-time Localization
  62. Swift GRB210825.29: Global MASTER-Net observations report
  63. GRB 210822A: VLA detection
  64. Swift detection of an outburst from SGR Swift J1555.2-5402
  65. GRB 210822A: Swift/UVOT Detection
  66. Swift GRB 210824A: Global MASTER-Net observations report
  67. GRB 210824A: BOOTES-5/JGT optical upper limit
  68. GRB 210824A: Fermi GBM Observation
  69. GRB 210824A: Nanshan/NEXT optical upper limit
  70. GRB 210824A: Swift-XRT refined Analysis
  71. GRB 210822A: GROND observations
  72. GRB 210824A: Enhanced Swift-XRT position
  73. GRB 210824A: Swift detection of a burst
  74. GRB 210824A: Fermi GBM Final Real-time Localization
  75. GRB 210822A: Detection by GRBAlpha
  76. GRB 210822A: GECAM refined analysis
  77. GRB 210820A: GROND observations
  78. Konus-Wind detection of GRB 210822A
  79. GRB 210822A: AstroSat CZTI detection
  80. GRB 210822A: Swift-XRT refined Analysis
  81. GRB 210822A: Swift-BAT refined analysis
  82. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  83. GRB 210822A: Fermi-LAT detection
  84. GRB 210820A: Swift/UVOT Detection
  85. GRB 210822B: Fermi GBM Final Real-time Localization
  86. GRB 210822A: Enhanced Swift-XRT position
  87. Swift GRB 210822A: Global MASTER-Net observations report
  88. GRB 210822A: KAIT Optical Afterglow Confirmation
  89. GRB 210822A: GECAM detection
  90. GRB 210822A: Swift detection of a burst with an optical afterglow
  91. GRB 210820A: Swift-BAT refined analysis
  92. GRB 210820A: LT optical upper limit
  93. GRB 210820A: LCO Optical Upper Limit
  94. GRB 210820A: RATIR Optical Detections
  95. GRB 210821A: Fermi GBM Final Real-time Localization
  96. GRB 210820A: NOT optical upper limit
  97. GRB 210820A: Nanshan/NEXT optical upper limit
  98. GRB 210820A: Swift-XRT refined Analysis
  99. GRB 210820A: Enhanced Swift-XRT position
  100. Swift GRB 210820A: Global MASTER-Net observations report

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