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

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 circle dot and mass M = 0.56 +/- 0.07 M circle dot 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 circle dot, and L = 56.0 +/- 4.2 L circle dot. 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.