A Study of the Pulsation Properties of 57 Non-Blazhko Ab-type RR Lyrae Stars with Homogeneous Metallicities from the LAMOST–Kepler/K2 Survey

Abstract Homogeneous metallicities and continuous high-precision light curves play key roles in studying the pulsation properties of RR Lyrae stars. By cross matching LAMOST DR6 with Kepler K2 fields, we have determined seven 50 non-Blazhko RRab stars, respectively, that homogeneous from low-resolution spectra LAMOST–Kepler/K2 survey. The Fourier decomposition method is applied to these stars provided by space-based telescope determine fundamental periods parameters. calculated amplitude ratios R 21 , 31 phase differences ϕ are consistent parameters both globular clusters Large Magellanic Cloud. We find a linear relationship between which good agreement results literature. As far as amplitude, primary frequency A 1 total tot follow either cubic or relationship. For rise time, do not its relevance period mode P . However, it might Based on metallicities, derived new calibration formula for period– –[Fe/H] relation, agrees well previous studies.