2020MNRAS.493.1565D

A comprehensive photometric and spectroscopic analysis of the variable TYC 5532-1333-1 (TYC) along with an investigation of its orbital period variation is presented for the first time. The B- and V-band photometric study indicates that TYC is an intermediate contact binary with degree of contact and mass ratio of 34 per cent and ∼0.24, respectively. The derived equivalent widths from the spectroscopic study of Hα and Na-I lines reveal phase-dependent variation and mutual correlation. Using the available times of minimum light, an investigation of orbital period variation shows a long-term decrease at a rate of 3.98 x 10^–6 d/yr. Expected causes for such decline in the orbital period could be angular momentum loss and a quasi-sinusoidal variation due to light-time effect probably caused by a third-body companion. The minimum mass of the third body (M3) was derived to be 0.65 M_{☉}. Our presented study is an attempt to evaluate and understand the evolutionary state of above-mentioned neglected contact binary.