Estimation of the Galactocentric Distance of the Sun from Cepheids Close to the Solar Circle

Abstract

Based on Cepheids located near the solar circle, we have determined the Galactocentric distance of the Sun $R_0$ and the Galactic rotation velocity at the solar distance $V_0$. For our analysis we used a sample of $\sim$200 classical Cepheids from the catalogue by Skowron et al. (2019), where the distances to them were determined from the period-luminosity relation. For these stars the proper motions and line-of-sight velocities were taken from the Gaia DR3 catalogue. The values of $R_0$ found lie within the range [7.8-8.3] kpc, depending on the heliocentric distance of the sample stars, on the adopted solar velocity relative to the local standard of rest, and on whether or not the perturbations caused by the Galactic spiral density wave are taken into account. The dispersion of the $R_0$ estimates is $\sim$2 kpc. Similarly, the values of $V_0$ lie within the range [240-270] km s$^{-1}$ with a dispersion of the estimates of 70-90 km s$^{-1}$. We consider the following estimates to be the final ones: $R_0=8.24\pm0.20$ kpc and $V_0=268\pm8$ km s$^{-1}$ found by taking into account the perturbations from the Galactic spiral density wave.