The local standard of rest from data on young objects with account for the Galactic spiral density wave

Abstract

To estimate the peculiar velocity of the Sun with respect to the local standard of rest (LSR), we used young objects in the Solar neighbourhood with distance measurement errors within 10-15 per cent. These objects were the nearest Hipparcos stars of spectral classes O-B2.5, masers with trigonometric parallaxes measured by means of very long baseline interferometry, and two samples of the youngest and middle-aged Cepheids. The most significant component of motion of all these stars is induced by the spiral density wave. As a result of using all these samples and taking into account the differential Galactic rotation, as well as the influence of the spiral density wave, we obtained 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 have found that components of the Solar velocity are quite insensitive to errors of the distance R₀ in a broad range of its values, from R₀ = 7.5 kpc to R₀ = 8.5 kpc, that affect the Galactic rotation curve parameters. In the same time, the Solar velocity components (U_⊙)_LSR and (V_⊙)_LSR are very sensitive to the Solar radial phase χ_⊙ in the spiral density wave.