Orbital Solutions of the New Low-mass Eclipsing Binary TIC 157376469 with Spotted Activities

Abstract

We carried out a photometric and spectroscopic analysis for the eclipsing binary TIC 157376469 using the TESS and LAMOST data. A new linear ephemeris is given. By fitting the light curves and radial velocity curves with the Wilson-Devinney code, it apperas that the binary is composed of two K-type main-sequence stars. The orbit of the binary is slightly eccentric ( $e\approx 0.0017$ ) and the primary is a spotted active star. The masses and radii of the two components are determined to be ${M}_{1}=0.704\pm 0.028{M}_{\odot }$ , ${R}_{1}=0.754\pm 0.010{R}_{\odot }$ , ${M}_{2}=0.539\pm 0.021{M}_{\odot }$ , ${R}_{2}=0.543\pm 0.007{R}_{\odot }$ , respectively. The temperature ratio ( ${T}_{2}/{T}_{1}$ ) is determined to be ∼0.879. Under a assumption that the primary temperature is ${T}_{1}=4740{\rm{K}}$ , comparisons to the PARSEC v1.2 isochrones show that for the primary the radius is oversized of ∼16%, and the effective temperature is cooler of $\sim 300{\rm{K}}$ (∼6%). While, the properties of the secondary are almost in agreement with the predictions of the model.