The first photometric and dynamical study of the eclipsing binary star V951 Perseus

In this paper, we studied the short-period eclipsing binary V951 Perseus (hereafter V951 Per) using the newly observed four-color ($B$, $V$, $R_c$, $I_c$) light curves and the TESS data. Photometric solutions suggest that it is a W-subtype shallow contact binary with a mass ratio of $q$ = 1.95 and a contact degree of $f$ = 7.0%. In order to fit the asymmetrical light curves well, a cool star-spot on the less massive component is employed. Based on our new CCD eclipsing times and the data published until now, changes in the eclipsing times were analyzed using the $O-C$ method. The $O-C$ diagram indicates that the orbital period of V951 Per is decreasing at a rate of $dP/dt$ = −8.79 × 10⁻⁸ d yr⁻¹, superposed on a cyclic oscillation with an amplitude of 0.0046 d and a period of 11.4 yr. The secular period decrease can be explained by the mass transfer from the more massive component to the less massive one or by the angular momentum loss. The cyclic oscillation may be interpreted as the light-travel-time effect because of the presence of an unseen third body. We calculated the mass of the third companion as $M_{3}sin\left(i\right)$ = 0.18 $M_{\odot }$.