Accurate Fourier Decomposition of Cepheid Radial Velocity Curves

Abstract

Abstract The shapes of light curves and of radial velocity curves are two main predictions of the hydrodynamical models of Cepheids. Of the two, the velocity curves are more robust numerically and therefore, more suitable for comparison with the observations. In this report, we present accurate Fourier parameters for an extensive set of classical Cepheid velocity curves. Published radiative models reproduce the observations very well, with only small discrepancies present. We estimate the center of the ω 2 = 2ω 0 resonance to occur at P r = 9.947 ± 0.051 day