Fermi GBM trigger 805929723: Probable non-GRB transient with 47% confidence
AI Summary
Fermi GBM detected a transient event on 2026-07-16 at 21:21:58.61 UTC with a significance of 9.7-9.8σ over 16 ms timescale. The automated classification indicates only 47% probability of GRB origin, with AGN (36%) as the second-most likely classification. The event was localized to RA=260.07°, Dec=-5.92° with a 14.2° error radius, showing a hardness ratio of 2.74 and burst intensity of 1537 counts. No follow-up observations or GCN circulars have been issued, and the delayed transmission flag suggests this was a flight-generated alert with marginal astrophysical significance.
Measurements
| Event ID | 805929723 |
|---|---|
| Source | Fermi GBM |
| Alert type | GRB |
| Significance | low |
| Trigger time (UTC) | Thu, 16 Jul 2026 21:21:58 GMT |
| Right ascension (J2000) | 260.0667° |
| Declination (J2000) | -5.9167° |
| Position error radius | 14.2333° |
| GCN notices | 2 |
| GCN circulars | 0 |
Notices (1)
Fermi GBM — GRB · Thu, 16 Jul 2026 21:21:58 GMT
AI summary generated Sat, 18 Jul 2026 14:58:40 GMT.