Long-term Photometric and Low-resolution Spectroscopic Analysis of Five Contact Binaries

Abstract

A photometric and spectroscopic investigation is performed on five W Ursae Majoris eclipsing binaries J015818.6 +260247 (hereinafter as J0158b), J073248.4+405538 (hereinafter as J0732), J101330.8+494846 (hereinafter as J1013), J132439.8+130747 (hereinafter as J1324), and J152450.7+245943 (hereinafter as J1524). The photometric data are collected with the help of the 1.3 m Devasthal Fast Optical Telescope, the 1.04 m Sampurnanand Telescope, and the Transiting Exoplanet Survey Satellite space mission. The low-resolution spectra of the 4 m Large Sky Area Multi-Object Fiber Spectroscopic Telescope are used for spectroscopic analysis. The orbital period change of these systems is determined using our photometric data and previously available photometric data from different surveys. The orbital period of J1013 and J1524 is changing at a rate of −2.552 (±0.249) × 10−7 days yr−1 and −6.792( ±0.952) × 10−8 days yr−1 , respectively, while others do not show any orbital period change. The orbital period change of J1013 and J1524 corresponds to a mass transfer rate of 2.199 × 10−7 and 6.151 × 10−8 Me yr−1 from the primary to the secondary component in these systems. It is likely that angular momentum loss via magnetic braking may also be responsible for the observed orbital period change in the case of J1524. All systems have a mass ratio lower than 0.5, except J0158b with a mass ratio of 0.71. All the systems are shallow-type contact binaries. J0158b and J1524 are subtype A while others are subtype W. The Hα emission line region is compared with template spectra prepared using two inactive stars with the help of the STARMOD program. The J0158, J1324, and J1524 systems show excess emission in the residual spectra after subtraction of the template.