Local kinematics and the local standard of rest

We re-examine the stellar kinematics of the solar neighbourhood in terms of the velocity υ⊙ of the Sun with respect to the local standard of rest. We show that the classical determination of its component V⊙ in the direction of Galactic rotation via Strömberg's relation is undermined by the metallicity gradient in the disc, which introduces a correlation between the colour of a group of stars and the radial gradients of its properties. Comparing the local stellar kinematics to a chemodynamical model which accounts for these effects, we obtain (U, V, W)⊙ = (11.1+0.69-0.75, 12.24+0.47-0.47, 7.25+0.37-0.36) km s-1, with additional systematic uncertainties ∼(1, 2, 0.5) km s-1. In particular, V⊙ is 7 km s-1 larger than previously estimated. The new values of (U, V, W)⊙ are extremely insensitive to the metallicity gradient within the disc. © 2010 The Authors. Journal compilation © 2010 RAS