Asteroseismological Analysis of the Non-Blazhko RRab Star EPIC 248846335 in the LAMOST–Kepler/K2 Project

Autor: Peng Zong, Jian-Ning Fu, Jie Su, Xueying Hu, Bo Zhang, Jiaxin Wang, Gao-Chao Liu, Gang Meng, Gianni Catanzaro, Antonio Frasca, Haotian Wang, Weikai Zong
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: The Astronomical Journal, Vol 167, Iss 5, p 227 (2024)
Druh dokumentu: article
ISSN: 1538-3881
97134228
DOI: 10.3847/1538-3881/ad3357
Popis: We conduct an asteroseismological analysis on the non-Blazhko ab-type RR Lyrae star EPIC 248846335, employing the Radial Stellar Pulsations module of the Modules for Experiments in Stellar Astrophysics based on the set of stellar parameters. The atmospheric parameters T _eff = 6933 ± 70 K, log g = 3.35 ± 0.50, and [Fe/H] = −1.18 ± 0.14 are estimated from low-resolution spectra of LAMOST DR9. The luminosity L = ${49.70}_{-1.80}^{+2.99}$ L _⊙ and mass M = 0.56 ± 0.07 M _⊙ are calculated, respectively, using the distance provided by Gaia and the metallicity estimated from the low-resolution spectra. The Fourier parameters of the light curves observed by K2 and radial velocity (RV) curves determined from the medium-resolution spectra of LAMOST DR10 are also calculated in this work. The period of the fundamental mode of the star and the residuals r of the Fourier parameters between the models and observations serve to select an optimal model, whose stellar parameters are T _eff = 6700 ± 220 K, log g = 2.70, [Fe/H] = −1.20 ± 0.2, M = 0.59 ± 0.05 M _⊙ , and L = 56.0 ± 4.2 L _⊙ . The projection factors are constrained as 1.20 ± 0.02 and 1.59 ± 0.13 by the blue- and red-arm observed velocities with their corresponding RV curves derived from the best-fit model, respectively. The precise determination of stellar parameters in ab-type RR Lyrae stars is crucial for understanding the physical processes that occur during pulsation and for providing a deeper understanding of their period–luminosity relationship.
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