The solar type deep low mass-ratio contact binary V658 Lyr: Photometric solution and preliminary elements

We present the first light curve analysis of the eclipsing binary V658 Lyr.

B, V and I_c photometric observations made from 2014 to 2017 of this W UMa-type binary star are collected, the complete light curves were obtained in 2015 (4 nights) and 2016 (11 nights) and are used for a detailed photometric analysis to determine orbital and physical parameters using the Wilson-Devinney code.

The results obtained indicates that V658 Lyr is an A-type overcontact binary system with both components of spectral type (G2 + G4).

Based on our 17 ToM the short orbital period of the eclipsing binary was confirmed and revised to P = 0.3302577 days.

The orbital period was found to show a cyclic variations and a decrease rate of dP/dt = - 2.97 × 10 -⁷ days yr-¹ , which can be interpreted as a mass transfer from the more massive component to the less massive one.

We have not found an asymmetry of the light curves.

The mass of the primary and secondary stars are calculated to be M₁ = 1.18M_⊙( ± 0.08) and M₂ = 0.21M_⊙( ± 0.01) indicating the primary to be underluminous for its mass and the secondary to be overluminous for its mass.