Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. 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').

21226 results found.

  1. GRB 240402C: Glowbug gamma-ray detection
  2. GRB 240405A: Fermi GBM Final Real-time Localization
  3. GRB 240402C: GRBAlpha detection
  4. Swift satellite resumes pointed science observations
  5. GRB 240403B: Glowbug gamma-ray detection
  6. GRB 240403A: Fermi GBM Detection
  7. Fermi GRB 240404A: Global MASTER-Net observations report
  8. GRB 240404A: Fermi GBM Final Real-time Localization
  9. LXT 240402A: MASTER optical observations with AGN in error-box
  10. GRB 240403A: BALROG localization (Fermi Trigger 733838255 / GRB 240403498)
  11. Fermi trigger No 733808041: Global MASTER-Net observations report
  12. Fermi GRB 240402A: Global MASTER-Net observations report
  13. GRB 240402A: Fermi GBM Final Real-time Localization
  14. X-ray transient EP240331a: Kinder optical upper limits
  15. EP240331A: MASTER optical observations
  16. Integral GRB240401.69: Global MASTER-Net observations report
  17. GRB 240331A: Fermi GBM Final Real-time Localization
  18. Fermi trigger No 733366352: Global MASTER-Net observations report
  19. Fermi GRB 240329A: Global MASTER-Net observations report
  20. GRB 240329A: BALROG localization (Fermi Trigger 733441392 / GRB 240329905)
  21. GRB 240329A: Fermi GBM Final Real-time Localization
  22. Fermi GRB 240328B: Global MASTER-Net observations report
  23. Fermi GRB 240328A: Global MASTER-Net observations report
  24. GRB 240328B: Fermi GBM Final Real-time Localization
  25. GRB 240328A: Fermi GBM Final Real-time Localization
  26. IceCube Alert 240327.68: Global MASTER-Net observations report
  27. Fermi trigger No 733097506: Global MASTER-Net observations report
  28. Fermi trigger No 733092476: Global MASTER-Net observations report
  29. Fermi trigger No 732937833: Global MASTER-Net observations report
  30. GRB 240318A: Fermi GBM Observation
  31. Fermi GRB 240320A: Global MASTER-Net observations report
  32. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  33. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  34. Fermi trigger No 732657380: Global MASTER-Net observations report
  35. GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  36. GRB 240320A: Fermi GBM Final Real-time Localization
  37. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  38. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  39. Fermi Gamma-ray Burst Monitor trigger 732299243/240316686 is not a GRB
  40. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  41. GRB 240317B: Fermi GBM Observation
  42. Fermi GRB 240318A: Global MASTER-Net observations report
  43. GRB 240318A: Fermi GBM Final Real-time Localization
  44. GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
  45. Fermi GRB 240317B: Global MASTER-Net observations report
  46. Fermi GRB 240317A: Global MASTER-Net observations report
  47. GRB 240317B: Fermi GBM Final Real-time Localization
  48. GRB 240317A: Fermi GBM Final Real-time Localization
  49. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  50. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  51. Fermi trigger No 732299243: Global MASTER-Net observations report
  52. GRID detection of GRB 240306A
  53. Changes to the Fermi-GBM Triggering Thresholds
  54. GRB 240315A: Fermi GBM Final Real-time Localization
  55. Fermi GRB 240314A: Global MASTER-Net observations report
  56. GRB 240314A: Fermi GBM Final Real-time Localization
  57. GRB 240312A: Glowbug gamma-ray detection
  58. Swift Trigger 1219909 and 1219910 are not a astrophysical
  59. Swift Trigger 1219905 is not a GRB
  60. Swift Trigger 1219874 is not astrophysical
  61. GRB 240303C: VZLUSAT-2 detection
  62. Fermi trigger No 731839490: Global MASTER-Net observations report
  63. GRB 240310B: Glowbug gamma-ray detection
  64. Fermi GRB 240310A: Global MASTER-Net observations report
  65. Swift GRB240309.61: Global MASTER-Net observations report
  66. GRB 240310A: Fermi GBM Final Real-time Localization
  67. Swift Trigger 1219325 is not a GRB
  68. GRB 240308A: Fermi GBM Final Localization
  69. Fermi trigger No 731571927: Global MASTER-Net observations report
  70. GRB 240306A: Fermi GBM observation
  71. IceCube Alert 240307.32: Global MASTER-Net observations report
  72. Konus-Wind detection of GRB 231118A
  73. GRB 240306A: AstroSat CZTI detection
  74. Fermi GRB 240306A: Global MASTER-Net observations report
  75. Fermi GRB 240305A: Global MASTER-Net observations report
  76. GRB 240306A: Swift/BAT-GUANO detection of a burst
  77. GRB 240305A: Fermi GBM observation
  78. GRB 240306A: Fermi GBM Final Real-time Localization
  79. Swift GRB240305.18: Global MASTER-Net observations report
  80. Swift GRB240305.16: Global MASTER-Net observations report
  81. Fermi GRB 240305C: Global MASTER-Net observations report
  82. GRB 240305C: Fermi GBM Final Real-time Localization
  83. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  84. GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
  85. GRB 240218A: Chandra Detection and Jet Break Confirmation
  86. GRB 240305B: Fermi GBM Final Localization
  87. Fermi trigger No 731303574: Global MASTER-Net observations report
  88. Konus-Wind detection of GRB 240227A (short/hard)
  89. IPN triangulation of GRB 240229A
  90. GRB 240305A: Fermi GBM Final Real-time Localization
  91. Swift Trigger 1218701: Yes, we triggered on Swift J151857.0-572147 again
  92. Swift Trigger 1218696: Another trigger on Swift J151857.0-572147
  93. Swift Trigger 1218645: Another detection of Swift J151857.0-572147
  94. IPN triangulation of GRB 240303B
  95. Swift J151857.0-572147: Swift-BAT refined analysis
  96. GRB 240303B: Fermi GBM Detection
  97. Swift detection of Swift J151857.0-572147
  98. GRB 240303B: CALET Gamma-Ray Burst Monitor detection
  99. Fermi trigger No 731161136: Global MASTER-Net observations report
  100. GRB 240303C: BALROG localization (Fermi Trigger 731189113 / GRB 240303837)

Advanced

Download all Circulars as a .tar.gz archive:
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