Photometric and Spectroscopic Analysis of V583 Lyrae, an Algol with a g-mode Pulsating Primary and Accretion Disk

Abstract

V583 Lyr is an extremely low-mass-ratio Algol-type binary with an orbital period of 11.2580 days. We determined an effective temperature of T eff1 = 9000 ± 350 K from newly observed spectra, which might be an underestimate due to binary mass transfer. The binary mass ratio q = 0.1 ± 0.004 and the orbital inclination i = 85.°5 are determined based on the assumption that the secondary fills its Roche lobe and rotates synchronously. The radial velocity curve is obtained from time series spectra, allowing for improved estimation of stellar masses and radii: M 1 = 3.56 ± 0.5 M ⊙, R 1 = 2.4 ± 0.2 R ⊙; and M 2 = 0.36 ± 0.02 M ⊙, R 2 = 6.9 ± 0.4 R ⊙. The variations in the double-peaked Hα emission indicate the formation of a stable disk during mass transfer. V583 Lyr appears to be a post-mass-reversal system, according to the mass transfer estimated using O − C period analysis. Its orbital period is slowly increasing, from which the rate of mass accretion by the primary star is estimated to be M 1 ̇ = 3.384 × 10−8 M ⊙ yr−1. The pulsation analysis was conducted on the residuals of the light curve. The primary component was found to be a g-mode pulsating star with 26 frequencies extracted lower than 9 day−1. The frequency groups and rotational splitting properties of the g mode were studied in detail. This study provides compelling evidence for an accretion disk surrounding the g-mode pulsating primary.