We present a spectroscopic and photometric study of the Double Period Variable HD170582. Based on the study of the ASAS V-band light curve we determine an improved orbital period of 16.87177 $pm$ 0.02084 days and a long period of 587 days. We disenta
ngled the light curve into an orbital part, determining ephemerides and revealing orbital ellipsoidal variability with unequal maxima, and a long cycle, showing quasi-sinusoidal changes with amplitude $Delta V$= 0.1 mag. Assuming synchronous rotation for the cool stellar component and semi-detached configuration we find a cool evolved star of $M_{2}$ = 1.9 $pm$ 0.1 $M_{odot}$, $T_{2}$ = 8000 $pm$ 100 $K$ and $R_{2}$ = 15.6 $pm$ 0.2 $R_{odot}$, and an early B-type dwarf of $M_{1}$ = 9.0 $pm$ 0.2 $M_{odot}$. The B-type star is surrounded by a geometrically and optically thick accretion disc of radial extension 20.8 $pm$ 0.3 $R_{odot}$ contributing about 35% to the system luminosity at the $V$ band. Two extended regions located at opposite sides of the disc rim, and hotter than the disc by 67% and 46%, fit the light curve asymmetries. The system is seen under inclination 67.4 $pm$ 0.4 degree and it is found at a distance of 238 $pm$ 10 pc. Specially interesting is the double line nature of HeI 5875; two absorption components move in anti-phase during the orbital cycle; they can be associated with the shock regions revealed by the photometry. The radial velocity of one of the HeI 5875 components closely follows the donor radial velocity, suggesting that the line is formed in a wind emerging near the stream-disc interacting region.
The early B supergiant LMC star BI 108 is photometrically variable with a unique light curve; two strong periods are present in an almost precise 3:2 resonance. We collected spectroscopic data at VLT/UVES, sampling the supercycle of 10.733 days in te
n epochs. We find spectral signatures for a SB2 system consisting of two massive B1 supergiants orbiting at the orbital period of 5.366 days. The shorter periodicity resembles the light curve of an eclipsing binary with periodicity 3.578 days that is not detected in the data. We discuss possible causes for the short periodicity and conclude that the quadruple system is the more plausible hypothesis.
V393 Scorpii is a Double Periodic Variable characterized by a relatively stable non-orbital photometric cycle of 253 days. Mennickent et al. argue for the presence of a massive optically thick disc around the more massive B-type component and describ
e the evolutionary stage of the system. In this paper we analyze the behavior of the main spectroscopic optical lines during the long non-orbital photometric cycle. We study the radial velocity of the donor determining their orbital elements and find a small but significant orbital eccentricity (e = 0.04). The donor spectral features are modeled and removed from the spectrum at every observing epoch using the light-curve model given by Mennickent et al. We find that the line emission is larger during eclipses and mostly comes from a bipolar wind. We find that the long cycle is explained in terms of a modulation of the wind strength; the wind has a larger line and continuum emissivity on the high state. We report the discovery of highly variable chromospheric emission in the donor, as revealed by Doppler maps of the emission lines MgII 4481 and CI 6588. We discuss notable and some novel spectroscopic features like discrete absorption components, especially visible at blue-depressed OI 7773 absorption wings during the second half-cycle, Balmer double emission with V/R-curves showing Z-type and S-type excursions around secondary and main eclipse, respectively, and H_beta emission wings extending up to +- 2000 km/s. We discuss possible causes for these phenomena and for their modulations with the long cycle.
We present preliminary results of our spectroscopic campaign of a group of intermediate mass interacting binaries dubbed Double Periodic Variables (DPVs), characterized by orbital light curves and additional long photometric cycles recurring roughly
after 33 orbital periods (Mennickent et al. 2003, 2005). They have been interpreted as interacting, semi-detached binaries showing cycles of mass loss into the interstellar medium (Mennickent et al. 2008, Mennickent & Kolaczkowski 2009). High resolution Balmer and helium line profiles of DPVs can be interpreted in terms of mass flows in these systems. A system solution is given for LP Ara, based on modeling of the ASAS V-band orbital light curve and the radial velocity of the donor star.
