The distance to the galactic center from observations of the outer galaxy

Abstract

The method of Weaver (1954) to obtain the distance to the galactic center from observations on the solar circle is extended to include data at considerable distances from the solar circle. The circular velocity of the local standard of rest, θo, is a free parameter in the solution, but because of the large number of data points, a relative uncertainty of only 6% is attained. The derived distance, 8.0 ± 0.5 kpc for θ0 = 220 km s−1, is sensitive only to streaming motions with scale sizes larger than ≈ 10 kpc and to any zero point error in the stellar distance scale.