Early-type W UMa contact binary system: New data on V535 Ara

This paper presents the results of spectroscopic and photometric observations of the early-type W UMa system V535 Ara. New high-resolution spectra were taken at the Mt. John University Observatory in 2007. Radial velocities and spectroscopic orbital elements of the system were determined by applying KOREL spectral disentangling. The resulting orbital elements were: a₁sin i = 0.0047 ± 0.0001 AU, a₂sin i = 0.0146 ± 0.0001 AU, M₁sin ³i = 1.85 ± 0.01 M _⊙, and M₂sin ³i = 0.59 ± 0.01 M _⊙. The components were found to be in synchronous rotation following examination of their disentangled H γ line profiles. Four photometric data-sets (1966 BV, 1967 BV, HIPPARCOS and ASAS) were modeled using the Wilson-Devinney method. The model describes V535 Ara as an A sub-type W UMa type eclipsing binary which has a fill out factor of 0.22 in marginal contact configuration. The simultaneous solution of light and radial velocity curves gave the following absolute parameters: M₁ = 1.94 ± 0.04 M _⊙, M₂ = 0.59 ± 0.02 M _⊙, R₁ = 2.09 ± 0.03 R _⊙, R₂ = 1.23 ± 0.02 R_⊙, L₁ = 18 ± 3 L _⊙ and L₂ = 6 ± 1 L _⊙. The distance to V535 Ara was calculated as 123 ± 20 pc using distance modulus with correction for interstellar extinction.