Double Periodic Variables (DPV) are among the new enigmas of semi-detached eclipsing binaries. These are intermediate-mass binaries characterized by a long photometric period lasting on average 33 times the orbital period. We present a spectroscopic and photometric study of the DPV V495 Cen based on new high-resolution spectra and the ASAS V-band light curve. We have determined an improved orbital period of $33.492 \pm 0.002$ d and a long period of 1283 d. We find a cool evolved star of $M_{ 2}=0.91\pm 0.2 M_{ \odot}$, $T_{ 2}= 6000\pm 250 K$ and $R_{ 2}=19.3 \pm 0.5 R_{ \odot}$ and a hot companion of $M_{ 1}= 5.76\pm 0.3 M_{ \odot}$, $T_{ 1}=16960\pm 400 K$ and $R=4.5\pm0.2 R_{ \odot}$. The mid-type B dwarf is surrounded by a concave and geometrically thick disc, of radial extension $R_{ d}= 40.2\pm 1.3 R_{ \odot}$ contributing $\sim$ 11 percent to the total luminosity of the system at the V band. The system is seen under inclination $84.\!\!^{ \circ}8$ $\pm$ $0.\!\!^{ \circ}6$ and it is at a distance $d= 2092 \pm 104.6$ pc. The light curve analysis suggests that the mass transfer stream impacts the external edge of the disc forming a hot region 11 % hotter than the surrounding disc material. The persistent $V<R$ asymmetry of the H$\alpha$ emission suggests the presence of a wind and the detection of a secondary absorption component in He I lines indicates a possible wind origin in the hotspot region.
Categories: astro-ph.SR