Life after eruption - II. The eclipsing old nova V728 Scorpii

The old nova V728 Sco has been recently recovered via photometric and
spectroscopic observations, 150 years after the nova eruption. The
spectral properties pointed to a high-inclination system with a
comparatively low mass-transfer rate. In this paper we show that the
object is an eclipsing system with an orbital period of 3.32 h. It has
enhanced long-term variability that can be interpreted as ‘stunted’
dwarf-nova-type outbursts. Using the ingress and egress times of the
eclipsed components we calculate the radius of the central object. The
latter turns out to be significantly larger than a white dwarf and we
identify it with a hot inner disc. The implications for models on the
behaviour of post-novae are discussed.