Parameters of the Galactic rotation curve and spiral pattern from Cepheid kinematics

A method is developed for analyzing stellar velocity fields in our Galaxy, with allowance for spiral-density-wave perturbations. The parameters of the Galactic rotation curve, spiral pattern, and mean solar motion are inferre d using new Cepheid radial velocities and proper motions measured by the HI PPARCOS space telescope. The Sun is very close to the corotation circle, wh ere the velocity of the Galactic rotation coincides with the velocity of th e spiral pattern: the corotation radius is R-C approximate to 7.3 kpc, wher eas the radius of the solar circle is R-. approximate to 7.5 kpc.