Some Kinematical Properties of Solar Motion Using Stellar Associations

Abstract

In this paper, we have constructed many models of the Solar motion and the kinematical properties for a sample of 5100 main sequence stars; into which 1528 early types (B5, A0, A5, F0, and F5) and about 3572 late types (G0, G5, K0, and K5). The sample was collected with aid of Extended Hipparcos Compilation (XHIP) Cross references. Based on the space velocity vectors (U, V, W), we have computed velocity ellipsoid parameters of the stellar associations under study. For both early and late types, we have derived the following constants: the Galactic longitude l_A, Galactic latitude b_A, the Solar apex (alpha_A, delta_A), the Solar velocity S_Sun, the velocity dispersion (s1, s2, s3), the distance to the Galactic center R_gc, and the projected distances (X_Sun, Y_Sun, Z_Sun).