* Astronomy

Title: A photometric and spectroscopic study of WW And - an Algol-type, long period binary system with an accretion disc
Authors: Michal Siwak, Stanislaw Zola, Tomasz Szymanski, Maria Kurpinska-Winiarska, Maciej Winiarski, Dorota Koziel-Wierzbowska, Waclaw Waniak, Michal Drahus

We have analysed the available spectra of WW And and for the first time obtained a reasonably well defined radial velocity curve of the primary star. Combined with the available radial velocity curve of the secondary component, these data led to the first determination of the spectroscopic mass ratio of the system at q-spec = 0.16 ±0.03. We also determined the radius of the accretion disc from analysis of the double-peaked H-alpha emission lines. Our new, high-precision, Johnson VRI and the previously available Stromgren vby light curves were modelled with stellar and accretion disc models. A consistent model for WW And - a semidetached system harbouring an accretion disc which is optically thick in its inner region, but optically thin in the outer parts - agrees well with both spectroscopic and photometric data.

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