Spectroscopic and photometric investigations of the totally eclipsing contact binary V1320 Cas

• Published in: New astronomy Vol. 112; p. 102254
• Main Authors: Liu, Jian-Fei, Li, Kai, Chen, Xu, Li, Ke-Xin, Liu, Fei, Gao, Xing, Sun, Guo-You
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2024
• Subjects: Binaries; Close — binaries; Eclipsing — binaries; Stellar evolution — individual; Close — binaries; Binaries; Stellar evolution — individual; Eclipsing — binaries
• ISSN: 1384-1076; 1384-1092
• DOI: 10.1016/j.newast.2024.102254

We analyzed the light curve of the total eclipse contact binary V1320 Cas, obtained reliable photometric solutions, confirmed it to be a W-type contact binary with a mass ratio of 3.404 and a contact degree of 23.9%, a cool spot is discovered on the less massive component. Orbital period analysis indicates that the period of V1320 Cas is decreasing at a rate of dPdt=1.78×10−7 day yr−1, superimposed with a cyclic modulation with a period of 1.425 yr, long-term period decrease may be caused by the combination of mass transfer and angular momentum loss, and the cyclic modulation may be caused by the third companion. Using the photometric solutions and Gaia distance, we calculated the absolute physical parameters and plotted mass-luminosity and mass–radius diagrams to analyze the evolutionary status of V1320 Cas, the more massive component is a main sequence star, while the less massive component has higher luminosity and radius than those of main sequence stars with the same mass. With the decreasing orbital period, the two components of V1320 Cas will be gradually closer, while the binary may evolve toward deep contact. •We conducted photometric and spectroscopic analysis on V1320 Cas.•A cool spot was found on the less massive component of V1320 Cas.•Orbital period of V1320 Cas is long-term decreasing plus with a periodic variation.