Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

11519 results found.

  1. GRB 210622B: Fermi GBM Final Real-time Localization
  2. GRB 210622A: Fermi GBM Final Real-time Localization
  3. GRB 210619B: 1.5m OSN optical observation
  4. Fermi GRB 210621A: Global MASTER-Net observations report
  5. GRB 210621A: Fermi GBM Final Real-time Localization
  6. GRB 210619B: CALET Gamma-Ray Burst Monitor detection
  7. GRB 210619B: SRG/ART-XC detection
  8. GRB 210619B: Fermi GBM detection
  9. GRB 210619B: Xinglong TNT optical observations
  10. Konus-Wind detection of GRB 210619B
  11. GRB 210619B: CAHA 2.2m photometric monitoring
  12. GRB 210619B: Liverpool Telescope r'-band observations
  13. GRB 210619B: Fermi-LAT detection
  14. Fermi trigger No 645857659: Global MASTER-Net observations report
  15. GECAM detection of GRB 210619B
  16. GRB 210619A: BALROG localization (Fermi Trigger 645799548 / GRB 210619532)
  17. GRB 210619A: Fermi GBM Final Real-time Localization
  18. GRB 210618A: BOOTES-2/TELMA optical upper limit
  19. GRB 210618A: Fermi GBM observation
  20. GRB 210618A: DDOTI upper limit for the optical afterglow
  21. GRB 210618A: Fermi GBM Final Real-time Localization
  22. Fermi trigger No 645485036: Global MASTER-Net observations report
  23. GRB 201008A: Fermi GBM observation
  24. GRB 210323B: Fermi GBM observation
  25. Fermi GRB 210615A: Global MASTER-Net observations report
  26. GRB 210615A: Fermi GBM Final Real-time Localization
  27. GRB 210610A: Fermi GBM observations
  28. GRB 210421B: Fermi GBM detection
  29. GRB 201228B: Fermi GBM observation
  30. GRB 210606A: Fermi GBM detection
  31. GRB 210605B: Fermi GBM detection
  32. GRB 210610B: Fermi GBM detection
  33. Fermi trigger No 645047470: Global MASTER-Net observations report
  34. GRB 210610B: BALROG localization (Fermi Trigger 645047470 / GRB 210610827)
  35. GRB 210605A: CALET Gamma-Ray Burst Monitor detection
  36. Konus-Wind detection of GRB 210606B
  37. Fermi-LAT Gamma-ray Observations of IceCube-210608A
  38. IceCube-210608A: not observable by Fermi-GBM
  39. IPN triangulation of GRB 210606B
  40. IceCube-210608A: IceCube observation of a high-energy neutrino candidate track-like event
  41. Fermi Gamma-ray Burst Monitor trigger 644793834 / 210607892 is not a GRB
  42. Fermi trigger No 644793834: Global MASTER-Net observations report
  43. GRB 210606B: Fermi GBM detection
  44. Konus-Wind detection of GRB 210605A (short/hard)
  45. IPN triangulation of GRB 210605A (short)
  46. GRB 210606B: AGILE detection
  47. GRB 210606A: 1.5m OSN optical upper limit
  48. GRB 210606B: BALROG localization (Fermi Trigger 644712030 / GRB 210606945)
  49. GRB 210606B: GECAM detection
  50. Fermi trigger No 644712030: Global MASTER-Net observations report
  51. Fermi GRB 210606A: DDOTI Upper Limits on the Afterglow
  52. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  53. Fermi GRB 210606A: Global MASTER-Net observations report
  54. GRB 210606A: Fermi GBM Final Real-time Localization
  55. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  56. GRB 210605B: Fermi GBM Final Real-time Localization
  57. Fermi GRB 210605A: Global MASTER-Net observations report
  58. GRB 210605A: Fermi GBM Final Real-time Localization
  59. Fermi GBM Sub-Threshold Detection of new Swift SGR J1555.2-5402
  60. Fermi trigger No 644449593: Global MASTER-Net observations report
  61. GRB 210602B: GECAM detection
  62. GRB 210529A: GECAM detection
  63. Fermi trigger No 644359567: Global MASTER-Net observations report
  64. Fermi GRB 210601A: Global MASTER-Net observations report
  65. GRB 210601A: Fermi GBM Final Real-time Localization
  66. IPN triangulation of GRB 210531A
  67. GRB210529B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 644025222)
  68. GRB 210531A: AstroSat CZTI detection
  69. Fermi trigger No 644155206: Global MASTER-Net observations report
  70. GRB 210531A: AGILE/MCAL detection (Fermi Trigger 644155206 / GRB 210531500)
  71. GRB 210531A: BALROG localization (Fermi Trigger 644155206 / GRB 210531500)
  72. GRB 210529B: DDOTI Upper Limits on the Afterglow
  73. Fermi GRB 210529A: Global MASTER-Net observations report
  74. Fermi GRB 210529B: Global MASTER-Net observations report
  75. GRB 210529B: Fermi GBM Final Real-time Localization
  76. GRB 210529A: Fermi GBM Final Real-time Localization
  77. GRB 210528A: Fermi GBM detection
  78. GRB 210528A: AstroSat CZTI detection
  79. Fermi GRB 210528A: Global MASTER-Net observations report
  80. GRB 210528A: BALROG localization (Fermi Trigger 643903431 / GRB 210528586)
  81. GRB 210528A: Fermi GBM Final Real-time Localization
  82. Fermi GRB 210524B: DDOTI Upper Limits on the Afterglow
  83. Konus-Wind detection of GRB 210524A
  84. IPN triangulation of GRB 210524A
  85. Fermi trigger No 643548039: Global MASTER-Net observations report
  86. GRB 210524B: Fermi GBM Final Real-time Localization
  87. GRB 210524A: BALROG localization (Fermi Trigger 643525204 / GRB 210524208)
  88. Fermi GRB 210524A: Global MASTER-Net observations report
  89. GRB 210524A: Fermi GBM Final Real-time Localization
  90. GRB 210522A: GECAM detection
  91. GRB 210520A: Swift-XRT observations
  92. GRB 210520A: Fermi GBM detection
  93. GRB 210520A: Tiled Swift observations
  94. GRB 210520A: Fermi-LAT detection
  95. GRB 210520A: GECAM detection
  96. Fermi GRB 210520A: Global MASTER-Net observations report
  97. GRB 210520A: Fermi GBM Final Real-time Localization
  98. Fermi GBM observation of a bright burst from magneta
  99. Fermi GRB 210519A: Global MASTER-Net observations report
  100. IPN triangulation of GRB 210518A

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