STARITHM
Fermi GBM detects gamma-ray burst with ambiguous classification
AI Summary
Fermi GBM triggered on a gamma-ray transient at 2026-09-30T18:56:57.77Z (TrigID 812487422) with multiple position refinements. The flight-processed data classifies the source as AGN with 95% confidence, though ground-based localization suggests a weaker GRB association (50% probability). The burst shows a significance of 11.1σ in ground analysis with a 0.256s timescale and hardness ratio of 0.63, spanning 44-280 keV. Position estimates vary significantly across processing stages (9-73.3° localization errors), with the most refined ground position at RA=332.09°, Dec=25.24°. No follow-up circulars are currently available.
Measurements
| Event ID | 812487422 |
|---|---|
| Source | Fermi GBM |
| Alert type | GRB |
| Significance | medium |
| Trigger time (UTC) | Wed, 30 Sep 2026 18:56:57 GMT |
| Right ascension (J2000) | 119.52° |
| Declination (J2000) | 52.86° |
| Position error radius | 73.3° |
| GCN notices | 4 |
| GCN circulars | 0 |
Notices (1)
Fermi GBM — GRB · Wed, 30 Sep 2026 18:56:57 GMT
AI summary generated Wed, 30 Sep 2026 19:20:58 GMT.