Journal of Physical Studies 11(4), 457–460 (2007) DOI: https://doi.org/10.30970/jps.11.457 40 YEARS OBSERVATIONS AND SECONDARY RHYTHMS IN BETA LYRAE SYSTEM M. Yu. Skulsky National University ‟Lviv Polytechnics” 12 Bandera St., Lviv, UA–79013, Ukraine E-mail: mysky@polynet.lviv.ua

The crucial results of the spectral observations of the Beta Lyrae binary system are presented briefly. We determined directly the masses of both components as an important characteristic to the evolution status of this binary. The bright donor ($≈ 3 \; M_☉$) is losing its matter very actively in the rapid mass loss stage. The developed circumstellar gaseous structures and an accretion disk that camouflage the massive accretor ($≈ 13.5 \; M_☉$) are investigated. The disk's external part showed the precession motion. We discovered the donor's magnetic field that demonstrates the complicated time-dependent behavior and change on the long-time-scale variability. Also we analyzed the nonorbital secondary periods with the duration from 1.85$d$ to 340$d$ discovered in the last decades. In particular, the 1.85-day period could arise as the donor's nonradial oscillation that is in the resonant amplification of the tidal wave at the donor's surface. The 282.425-day period shows synchronization between the precession rotation of the accretion disk, disturbed by the donor, and the running tidal wave on the donor's surface caused by the accretor. The four substructures of the accretion disk are determined. The mass transfer processes in this interacting binary system are a determinative parameter in the phenomena of secondary rhythms and resonances.

PACS number(s): 97.80.Fk, 97.80.-d

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