STARITHM
Fermi GBM detects short transient classified as Terrestrial Gamma Flash (TGF)
AI Summary
Fermi GBM triggered on a brief gamma-ray transient at 2026-09-26 23:56:38.75 UTC (TrigID 812159803) with 100% confidence classification as a Terrestrial Gamma Flash (TGF), an atmospheric phenomenon of non-astrophysical origin. The event had a duration of 16 ms, significance of 5.7 sigma, and energy range from 291 keV to infinity. No follow-up observations are warranted given the TGF classification indicating atmospheric rather than cosmological origin.
Measurements
| Event ID | 812159803 |
|---|---|
| Source | Fermi GBM |
| Alert type | GRB |
| Significance | low |
| Trigger time (UTC) | Sat, 26 Sep 2026 23:56:38 GMT |
| Right ascension (J2000) | 286.5333° |
| Declination (J2000) | -33.9667° |
| Position error radius | 31.0333° |
| GCN notices | 2 |
| GCN circulars | 0 |
Notices (1)
Fermi GBM — GRB · Sat, 26 Sep 2026 23:56:38 GMT
AI summary generated Sun, 27 Sep 2026 06:45:57 GMT.