Kinematics of a sample of visual double stars

The Hipparcos-Input Catalogue also contains about 8000 already known visual double stars. In the framework of this-project campaign, in addition to other parameters, were also determined the parallaxes π, as well as the polar coordinates ρ and θ for double stars. On the basis of a comparison of these data to those obtained earlier from the ground based measurements (WDS Catalogue) statistical examinations of a double-star sample (1' ≤ ρ ≥ 14') are performed. It is shown that an exceptionally good agreement exists of the statistical distribution Δθ/Δt of the sample as function of ρ(AU) and the curve θ = C(ρ)/ρ2 representing the II Kepler law