A Photometric and Spectroscopic Study of the Short-period Algol EW Boötis with a δ Sct Pulsator

Abstract

In this paper, we present Transiting Exoplanet Survey Satellite (TESS) photometry and high-resolution spectra of the short-period Algol EW Boo. We obtained double-lined radial velocities (RVs) from the time-series spectra and measured the effective temperature of the primary star as T eff,1 = 8560 ± 118 K. For the orbital period study, we collected all times of minima available for over the last 30 yr. It was found that the eclipse timing variation of the system could be represented by a periodic oscillation of 17.6 ± 0.3 yr with a semiamplitude of 0.0041 ± 0.0001 day. The orbital and physical parameters were derived by simultaneously analyzing the TESS light and RV curves using the Wilson–Devinney (WD) binary star modeling code. The component masses and radii were showed over 3% precision: M 1 = 2.67 ± 0.08 M ⊙, M 2 = 0.43 ± 0.01 M ⊙, R 1 = 2.01 ± 0.02 R ⊙, and R 2 = 1.35 ± 0.01 R ⊙. Furthermore, multiple frequency analyses were performed for the light-curve residuals from the WD model. As a result, we detected 17 pressure-mode pulsations in the region of 40.15–52.37 day−1. The absolute dimensions and pulsation characteristics showed that the δ Sct pulsator was the more massive and hotter primary star of the EW Boo.