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"

11612 results found.

  1. Fermi GRB 251209A: Global MASTER-Net observations report
  2. Fermi GRB 251208C: Global MASTER-Net observations report
  3. GRB 251208B: Swift-XRT afterglow detection
  4. GRB 251209A: Fermi GBM Final Real-time Localization
  5. GRB 251208B: Fermi GBM Observation
  6. GRB 251208B: GROWTH-India Telescope optical upper limits
  7. GRB 251208A: SVOM/GRM observation of a short burst
  8. GRB 251208C: SVOM/GRM observation of a short burst
  9. GRB 251208B: Swift ToO observations
  10. GRB 251208B: Fermi-LAT detection
  11. GRB 251208B: Swift/BAT-GUANO arcminute localization of a burst
  12. GRB 251208C: Fermi GBM Final Real-time Localization
  13. GRB 251208B: Fermi GBM Final Real-time Localization
  14. GRB 251208A: Fermi GBM Final Real-time Localization
  15. Konus-Wind detection of GRB 251118A
  16. GRB 251126B: Fermi GBM Final Localization
  17. GRB 251203A: Insight-HXMT/HE detection
  18. GRB 251202A / EP251202a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm and 1-m telescopes at McDonald Observatory
  19. GRB 251202A: SVOM/GRM observation
  20. GRB 251203A: GECAM-B observation of a burst
  21. GRB 251203A: SVOM/GRM observation
  22. GRB 251201B: SALT spectroscopic redshift z = 1.599
  23. GRB 251203A: AstroSat CZTI detection
  24. Fermi Gamma-ray Burst Monitor trigger 786496343/251203967 is not a GRB
  25. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  26. GRB 251201B: Insight-HXMT/HE detection
  27. EP251202a / GRB 251202A: Insight-HXMT/HE detection
  28. GRB 251203A: Fermi GBM Final Real-time Localization
  29. EP251202a / GRB251202A: AstroSat CZTI detection
  30. GRB 251202A / EP251202a: SVOM/VT optical observation
  31. GRB 251201B: Fermi GBM Observation
  32. EP251202a/GRB 251202A: KAIT optical observations
  33. Fermi GRB 251202B: Global MASTER-Net observations report
  34. GRB 251202B: Fermi GBM Final Real-time Localization
  35. GRB 251202A: Fermi GBM Observation
  36. GRB 251201B: Kilonova-Catcher optical afterglow detection
  37. GRB 251130B: Glowbug gamma-ray detection
  38. GRB 251201B: GECAM-B observation of a long burst
  39. Fermi-LAT Gamma-ray Observations of IceCube-251130A
  40. EP251202a / GRB 251202A: LCO r- and i-band optical detection
  41. GRB 251202A: GOTO optical afterglow detection
  42. EP251202a / GRB 251202A: NOT spectroscopic redshift z = 2.785
  43. Fermi GRB 251202A: Global MASTER-Net observations report
  44. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  45. GRB 251202A: Fermi GBM Final Real-time Localization
  46. GRB 251201B: SVOM/VT optical fading
  47. Swift GRB 251201B : MASTER optical counterpart detection
  48. GRB 251201B: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at Sutherland Observatory
  49. GRB 251130B: AstroSat CZTI detection
  50. GRB 251201B: Fermi GBM Final Real-time Localization
  51. Fermi GRB 251130B: Global MASTER-Net observations report
  52. GRB 251127A: SVOM/GRM observation
  53. IceCube-251130A - IceCube observation of a high-energy neutrino candidate track-like event
  54. GRB 251130B: Fermi GBM Final Localization Correction
  55. GRB 251130B: Fermi GBM Final Real-time Localization
  56. GRB 251130A: Fermi GBM Final Real-time Localization
  57. GRB 251128A: AstroSat CZTI detection
  58. GRB 251128A: GECAM-B detection
  59. GRB 251128A: SVOM/GRM observation of a long burst
  60. GRB 251128A: Insight-HXMT/HE detection
  61. GRB 251128A: Fermi GBM Observation
  62. GRB 251128A: Swift/BAT-GUANO localization skymap of a burst
  63. Fermi GRB 251128A: Global MASTER-Net observations report
  64. GRB 251127A: Glowbug gamma-ray detection
  65. GRB 251128A: Fermi GBM Final Real-time Localization
  66. GRB 251125B: GECAM-B detection
  67. Fermi GRB 251127A: Global MASTER-Net observations report
  68. GRB 251127A: Fermi GBM Final Real-time Localization
  69. GRB 251121A: Fermi GBM Observation
  70. GRB 251125B: COLIBRÍ further observations and photometric redshift upper limit of z < 3
  71. GRB 251125B: COLIBRÍ observations of fading of the MASTER OT candidate
  72. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  73. Fermi GRB 251125B: Global MASTER-Net observations report
  74. GRB 251125B: Fermi GBM Final Real-time Localization
  75. Fermi GRB 251125A: Global MASTER-Net observations report
  76. GRB 251125A: Fermi GBM Final Real-time Localization
  77. GRB 251124A: Fermi GBM Localization by automated pipeline
  78. GRB 251122B: Fermi GBM Final Localization
  79. Fermi GRB 251124a: Global MASTER-Net observations report
  80. GRB 251124a: Fermi GBM Final Localization
  81. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  82. GRB 251121A: Glowbug gamma-ray detection of a likely short burst
  83. GRB 251115A: Fermi GBM Observation
  84. GRB 251121A: Fermi GBM Final Real-time Localization
  85. Fermi Gamma-ray Burst Monitor trigger 785388351 / 251121143 is not a GRB
  86. Fermi trigger No 785388351: Global MASTER-Net observations report
  87. GRB 251118A: Swift/UVOT Detection
  88. GRB 251118A: Glowbug gamma-ray detection
  89. GRB 251118A: Fermi GBM Observation
  90. GRB 251118A: Swift-XRT afterglow detection
  91. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  92. GRB 251118A: GECAM-B detection
  93. GRB 251118A: NuSTAR detection of bright prompt emission
  94. GRB 251117A: Swift-XRT observations
  95. GRB 251117A: Insight-HXMT/HE detection
  96. GRB 251118A: Fermi-LAT detection
  97. GRB 251118A: Swift ToO observations
  98. Fermi GRB 251118B: Global MASTER-Net observations report
  99. GRB 251118B: Fermi GBM Final Real-time Localization
  100. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations

Advanced

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