STARITHM
Fermi GBM detects gamma-ray burst with ambiguous classification
AI Summary
Fermi GBM triggered on a gamma-ray transient at 2026-10-03T01:18:35.14Z with a significance of 5.4-5.7σ and duration of 0.256s. The flight-based classification algorithm identifies the source as most likely an AGN (86% probability) with starbursting galaxy as secondary candidate (12%), suggesting a non-GRB origin. Ground-based localization provides coordinates RA=312.71°, Dec=53.88° with ~18° uncertainty, while flight-based position gives RA=310.02°, Dec=63.83° with ~27° uncertainty. The hardness ratio of 0.11 and energy range (44-280 keV) are consistent with a soft gamma-ray source. No follow-up circulars are available at this time.
Measurements
| Event ID | 812683120 |
|---|---|
| Source | Fermi GBM |
| Alert type | GRB |
| Significance | medium |
| Trigger time (UTC) | Sat, 03 Oct 2026 01:18:35 GMT |
| Right ascension (J2000) | 312.71° |
| Declination (J2000) | 53.88° |
| Position error radius | 18.09° |
| GCN notices | 3 |
| GCN circulars | 0 |
Notices (1)
Fermi GBM — GRB · Sat, 03 Oct 2026 01:18:35 GMT
AI summary generated Sat, 03 Oct 2026 01:24:34 GMT.