A Study of Pulsation properties of 57 Non-Blazhko effect 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 with LAMOST DR6, we have determined 7 and 50 Non-Blazhko RRab stars in the Kepler and K2 fields, respectively, who have homogeneous metallicities determined from low-resolution spectra of the LAMOST-Kepler/K2 project. The Fourier Decomposition method is applied to the light curves of these stars provided by the Kepler space based telescope to determine the fundamental pulsation periods and the pulsation parameters. The calculated amplitude ratios of R21, R31 and the phase differences of ϕ21, ϕ31 are consistent with the parameters of the RRab stars in both the Globular Clusters and the Large Magellanic Cloud. We find a linear relationship between the phase differences ϕ21 and ϕ31, which is in good agreement with the results in previous literature. As far as the amplitude, we find that the amplitude of primary frequency A1 and the total amplitude Atot follow either a cubic or linear relationship. For the rise time RT, we do not find its relevance with the period of the fundamental pulsation mode P1, or Atot and ϕ21. However, it might follow a linear relationship with R31. Based on the homogeneous metallicities, we have derived a new calibration formula for the relationship of period-ϕ31-[Fe/H], which agrees well with the previous studies.

References in corpus (17)

• EVEREST: Pixel Level Decorrelation of K2 Light curves
• The double Subgiant Branch of NGC 1851: the role of the CNO abundance
• Gaia Data Release 1 - The Cepheid & RR Lyrae star pipeline and its application to the south ecliptic pole region
• Kepler photometry of RRc stars: peculiar double-mode pulsations and period doubling
• Kepler photometry of the prototypical Blazhko star RR Lyr: An old friend seen in a new light
• Spectroscopic Comparison of Metal-Rich RRab Stars of the Galactic Field with Their Metal-Poor Counterparts
• Long time-scale behavior of the Blazhko effect from rectified Kepler data
• On the Use of Field RR Lyrae as Galactic Probes. II. A new $\Delta$S calibration to estimate their metallicity
• Chemical abundances of solar neighborhood RR Lyrae stars
• Pulsation models for the 0.26M_sun star mimicking RR Lyrae pulsator. Model survey for the new class of variable stars
• The RRC Stars: Chemical Abundances and Envelope Kinematics
• Metallicities from high resolution spectra of 49 RR Lyrae Variables
• Metallicity dependence of the Blazhko effect
• Palomar Transient Factory and RR Lyrae: Metallicity-Light Curve Relation Based on ab-Type RR Lyrae in Kepler Field
• Characteristics of bright ab-type RR Lyrae stars from the ASAS and WASP surveys
• The SERMON project: 48 new field Blazhko stars and an investigation of modulation-period distribution
• RRab variables with identical light-curve shapes at different pulsation periods

Cited by in corpus (1)

• High-cadence stellar variability studies of RR Lyrae stars with DECam: New multi-band templates