STARITHM
Fermi GBM trigger 813351696: Gamma-ray burst with ambiguous classification and poor localization
AI Summary
Fermi GBM detected a gamma-ray transient on 2026-10-10 at 19:01:31.45 UTC with a duration of ~2 seconds and significance of 4.6-7.4 sigma depending on analysis algorithm. The event shows conflicting classifications across multiple notices: early flight-based positions suggest unreliable localization or data artifacts ("BeginningOfFile" flags), while ground-based analysis favors AGN (57% probability) or SGR activity (32-34% probability) over a classical GRB. The energy range spans 44-280 keV with a hardness ratio of 1.5-1.7, consistent with a harder spectrum. Localization uncertainty ranges from 5 to 50 degrees, and delayed transmission flags indicate processing challenges, limiting immediate follow-up utility.
Measurements
| Event ID | 813351696 |
|---|---|
| Source | Fermi GBM |
| Alert type | GRB |
| Significance | medium |
| Trigger time (UTC) | Sat, 10 Oct 2026 19:01:31 GMT |
| Right ascension (J2000) | 0° |
| Declination (J2000) | 0° |
| Position error radius | 0° |
| GCN notices | 7 |
| GCN circulars | 0 |
Notices (1)
Fermi GBM — GRB · Sat, 10 Oct 2026 19:01:31 GMT
AI summary generated Mon, 12 Oct 2026 10:44:31 GMT.