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  • Asteroseismological Analysi...
    Zong, Peng; Fu, Jian-Ning; Su, Jie; Hu, Xueying; Zhang, Bo; Wang, Jiaxin; Liu, Gao-Chao; Meng, Gang; Catanzaro, Gianni; Frasca, Antonio; Wang, Haotian; Zong, Weikai

    The Astronomical journal, 05/2024, Letnik: 167, Številka: 5
    Journal Article

    Abstract 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.