2025MNRAS.540.3468P

The local Seyfert 1.5 active galactic nucleus, NGC 6814, is known to exhibit complex variability, eclipses, and even changing-look behaviour. In this work, we utilize optical-to-X-ray data obtained over 10 yr with the Neil Gehrels Swift Observatory to examine the short-term (i.e. daily) and long-term (yearly) variations in the spectral energy distribution (SED). This includes three epochs of high-cadence monitoring (2012, 2016, and 2022), as well as two single observations (2019 and 2021). Model-independent methods of examining the variability suggest that the three monitored epochs exhibit distinct behaviour. X-ray weakness in 2016 can be attributed to the previously studied eclipses, while similar behaviour in 2012 is associated with continuum changes and slight neutral absorption. The multi-epoch SED models are consistent with a black hole (${\log (M_{\rm BH}/\rm{\rm \, {\rm M}_{\odot }}{})\approx 7.6}$) that is accreting between $\dot{m}\approx 0.01-0.1$. While the corona (primary X-ray source) is compact, all epochs are better fit with an accretion disc inner radius that is much larger than the innermost stable circular orbit, implying the possibility of a non-standard accretion disc or central structure in NGC 6814.