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"

11546 results found.

  1. GRB 230506C: Fermi GBM detection
  2. Fermi trigger No 705413051: Global MASTER-Net observations report
  3. Fermi Gamma-ray Burst Monitor trigger 230510133/705381054 is not a GRB
  4. GRB 230510A: Fermi GBM Final Real-time Localization
  5. GRB 230307A: JWST second-epoch observations
  6. Fermi-LAT gamma-ray observations of IceCube-230506A
  7. IceCube-230506A: IceCube observation of a high-energy neutrino candidate
  8. GRB 230506A: Fermi GBM Final Real-time Localization
  9. Fermi trigger No 704837952: Global MASTER-Net observations report
  10. GRB 230503A: Fermi GBM Final Real-time Localization
  11. Konus-Wind detection of GRB 230430A
  12. IPN triangulation of GRB 230430A (short)
  13. GRB 230430B: Fermi GBM Final Localization
  14. GRB 230430A: Fermi GBM observation
  15. GRB 230430A: AstroSat CZTI detection
  16. GRB 230430A: Fermi GBM Final Real-time Localization
  17. GRB 230426A: VZLUSAT-2 detection
  18. Fermi trigger No 704365743: Global MASTER-Net observations report
  19. GRB 230428A: Fermi GBM Final Real-time Localization
  20. GRB 230426A: MASTER OT J023135.16-792104.8 optical counterpart discovery
  21. GRB 230426A: Fermi GBM Detection
  22. GRB 230426A: AstroSat CZTI detection
  23. Fermi trigger No 704233744: Global MASTER-Net observations report
  24. GRB 230426A: Fermi GBM Final Real-time Localization
  25. GRB 230425A: Fermi GBM Final Real-time Localization
  26. GRB 230421A: Fermi GBM observation
  27. Konus-Wind detection of GRB 230418A
  28. GRB 230421: Swift/BAT-GUANO arcminute localization
  29. Duplicate of GCN 33668
  30. GRB 230421A: Fermi GBM Final Real-time Localization
  31. IPN triangulation of GRB 230418A (short)
  32. GRB 230418A: AstroSat CZTI detection
  33. GRB 230418A: AGILE detection
  34. GRB 230402A: Fermi GBM detection
  35. GRB 230419A: Fermi GBM Final Real-time Localization
  36. GRB 230418A: Swift/BAT-GUANO detection outside the coded FOV
  37. GRB 230418A: Fermi GBM Observation
  38. GRB 230402A: Fermi-LAT detection
  39. Fermi-LAT gamma-ray observations of IceCube-230416A
  40. GRB 230415A: Fermi GBM detection
  41. GRB 230415A: Swift/BAT-GUANO detection
  42. GRB 230307A: iTelescope optical upper limit (likely)
  43. IceCube-230416A: IceCube observation of a high-energy neutrino candidate
  44. Fermi trigger No 703284533: Global MASTER-Net observations report
  45. Fermi GRB 230414A: Global MASTER-Net observations report
  46. GRB 230414A: Fermi GBM Final Real-time Localization
  47. GRB 230328B: redshift lower limit estimating
  48. GRB 230409D: VZLUSAT-2 detection
  49. GRB 230410A: Fermi GBM Final Real-time Localization
  50. Fermi GRB 230409C: Global MASTER-Net observations report
  51. Fermi GRB 230409A: Global MASTER-Net observations report
  52. GRB 230409C: Fermi GBM Final Real-time Localization
  53. Fermi trigger No 702745263: Global MASTER-Net observations report
  54. GRB 230409A: Fermi GBM Final Real-time Localization
  55. GRB 230405B: VZLUSAT-2 detection
  56. Fermi-LAT gamma-ray observations of IceCube-230405A
  57. Konus-Wind detection of GRB 230405B
  58. GRB 230405B: AGILE detection
  59. GRB 230405B: Fermi GBM Observation
  60. GRB 230307A: JWST NIRSpec observations, possible higher redshift
  61. GRB 230307A: short mininum variability timescale compatible with a merger origin
  62. GRB 230405B: AstroSat CZTI detection
  63. GRB 230405B: Fermi GBM Final Real-time Localization
  64. GRB 230307A: JWST observations consistent with the presence of a kilonova
  65. Fermi GRB 230405A: Global MASTER-Net observations report
  66. IceCube-230405A: IceCube observation of a high-energy neutrino candidate
  67. GRB 230405A: Fermi GBM Final Real-time Localization
  68. GRB 230404A: AstroSat CZTI detection
  69. GRB 230404A: Fermi GBM Final Real-time Localization
  70. GRB 230402A: CALET Gamma-Ray Burst Monitor detection
  71. GRB 230402A: AstroSat CZTI detection
  72. Fermi-LAT gamma-ray observations of IceCube-230401A and detection of Fermi J0030.2+0005
  73. GRB 230307A: Chandra late-time detection of the X-ray afterglow
  74. GRB 230402A: AGILE detection
  75. Fermi GRB 230402A: Global MASTER-Net observations report
  76. GRB 230402A: Fermi GBM Final Real-time Localization
  77. IceCube-230401A: IceCube observation of a high-energy neutrino candidate
  78. GRB 230307A: Bad Time Intervals for Fermi GBM data
  79. GRB 230328B : GRANDMA/Kilonova-Catcher optical detection
  80. GRB 230328B: CAHA 2.2m/CAFOS detection
  81. GRB 230328B: 3.6m DOT multiband optical observation
  82. Fermi trigger No 701883729: Global MASTER-Net observations report
  83. GRB 230330B: Fermi GBM Final Localization
  84. Konus-Wind detection of GRB 230328B
  85. GRB 230328B: GRBAlpha detection
  86. GRB 230330A: Fermi GBM Final Real-time Localization
  87. GRB 230328B: Liverpool Telescope afterglow detection
  88. GRB 230328B: AstroSat CZTI detection
  89. GRB 230328B: Fermi GBM observation
  90. GRB 230328B: Fermi GBM Final Real-time Localization
  91. Fermi GRB 230328A: Global MASTER-Net observations report
  92. GRB 230328A: Fermi GBM Final Real-time Localization
  93. GRB 230320B: Fermi GBM Observation
  94. Fermi trigger No 701313046: Global MASTER-Net observations report
  95. Fermi trigger No 701321709: Global MASTER-Net observations report
  96. Konus-Wind detection of GRB 230308A
  97. Konus-Wind detection of GRB 230304B
  98. GRB 230322A: Fermi GBM Final Real-time Localization
  99. GRB 230320B: GRBAlpha detection
  100. GRB 230321A: CALET Gamma-Ray Burst Monitor detection

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov