A New Estimate of the Local Standard of Rest from Data on Young Objects

Abstract

To estimate the peculiar velocity of the Sun with respect to the Local Standard of Rest (LSR), we use young objects in the Solar neighborhood with distance measurement errors within 10%–15%. These objects include the nearest Hipparcos O–B2.5 type stars, masers with VLBI trigonometric parallaxes, and two samples consisting of the youngest and middle-aged Cepheids. The most significant component of motion of all these stars is induced by the spiral density wave. An analysis of all these samples, taking into account differential Galactic rotation and the effect of the spiral density wave, yields the following components of the vector of the peculiar velocity of the Sun with respect to the LSR: (U⊙, V⊙, W⊙)LSR = (6.0, 10.6, 6.5) ± (0.5, 0.8, 0.3) km s−1. We found the Solar velocity components (U⊙)LSR and (V⊙)LSR to be highly sensitive to the Solar radial phase χ⊙ in the spiral density wave.

Keywords

• masers
• galaxy: kinematics and dynamics
• galaxy: local standard of rest