Spectroscopic and photometric analysis of the eclipsing binary HIP 7666 with δ Scuti pulsations
Esamdin, Ali; Wang, Liang; Cang, Tianqi; Fu, Jianning; Fox-Machado, Lester; Michel, Raul; Feng, Guojie; Ma, Lu; Bai, Chunhai; Niu, Hubiao; Iskandar, Abdusamatjan; Li, Chunqian; Zeng, Xiangyun; Liu, Nian; Xu, Jing; Pi, Qingfeng; Zhang, Yanping
China, Mexico
Abstract
New multicolour photometric observations were carried out on 22 nights in three observation missions between 2015 October and 2016 February for eclipsing binary HIP 7666. High- and low-resolution spectroscopic observations were also carried out in the winters of 2015, 2016, and 2019, respectively. The fully phase-covered light curves and radial velocity curves are presented. All times of light minima are used to calculate the orbital period [2.372 2200(4) d] and new ephemerides. The photometric solution and stellar physical parameters are derived, showing that HIP 7666 is a detached binary with the absolute parameters M1 = 1.53(3) M⊙, R1 = 2.08(2) R⊙, log L1/L⊙ = 0.99(3), log g1 = 3.98(2), Mbol1 = 2.26(8), Teff,1 = 7100(100) K for the primary, and M2 = 1.23(3) M⊙, R2 = 1.06(2) R⊙, log L2/L⊙ = 0.13(4), log g2 = 4.47(2), Mbol2 = 4.4(1), Teff,2 = 6029(67) K for the secondary. The age of 1.69 Gyr and 1.755 Gyr are estimated from PARSEC isochrones and MESA evolutionary tracks, respectively. In Herzsprung-Russell (H-R) diagram, the primary component has evolved to the late stages, while the secondary still locates at the early stages of the main sequence. Frequency analysis yields three frequencies of f1 = 24.631(4) cd-1, f2 = 21.193(1) cd-1, and f3 = 28.07(7) cd-1. Comparisons between models and observations suggest that the primary component is most likely a p-mode non-radial δ Scuti oscillator.