Galactocentric distance of the Sun derived from kinematic data

Abstract

Based on radial velocity data and Hipparcos proper motions, we present a new determination of the Galactocentric distance based on a purely kinematic model. We have selected three subgroups of Galactic thin-disk components (O–B5 stars, classical Cepheids and Galactic open clusters) to trace the local structure and kinematics of the Galactic disk. Adopting the approximation of axisymmetric circular rotation, we have derived the Sun's distance to the Galactic Center, R 0 = 8.25 ± 0.79 kpc based on O–B5 stars, R 0 = 7.98 ± 0.79 kpc based on Galactic Cepheids and R 0 = 8.03 ± 0.70 kpc using open clusters, all of which are in excellent agreement with the current-best estimate of the Galactocentric distance.