STARITHM
Fermi GBM detected a Terrestrial Gamma-ray Flash (TGF) on 2026-09-28
AI Summary
Fermi GBM triggered on event 812304621 at 2026-09-28T16:10:16.56Z with a classification of Terrestrial Gamma-ray Flash (TGF) at 100% confidence. The burst had a duration of 0.016-0.032 seconds with a trigger significance of 5.4 sigma and intensity of 311 counts. TGFs are atmospheric phenomena of non-astrophysical origin, originating from Earth's upper atmosphere rather than cosmic sources, making this a low-significance detection for astrophysical purposes.
Measurements
| Event ID | 812304621 |
|---|---|
| Source | Fermi GBM |
| Alert type | GRB |
| Significance | low |
| Trigger time (UTC) | Mon, 28 Sep 2026 16:10:16 GMT |
| Right ascension (J2000) | 144.1333° |
| Declination (J2000) | -51.3667° |
| Position error radius | 32.2833° |
| GCN notices | 2 |
| GCN circulars | 0 |
Notices (1)
Fermi GBM — GRB · Mon, 28 Sep 2026 16:10:16 GMT
AI summary generated Mon, 28 Sep 2026 19:18:05 GMT.