Orientation of the FK 4 coordinates from the Washington observations of the sun and planets

An attempt is made to determine Delta-A and Delta-D independently from an analysis of observations of planets made over a long time interval. To evaluate these quantities, the 60-yr Washington series of observations of the sun, Mercury, and Venus (1911-1971) is selected. The observations are divided into nine groups according to the catalog to which they were referred; they are then reduced to the uniform FK 4 system. In all, approximately 14,000 pairs of alpha, beta measurements are included in the analysis. These are compared with Newcomb's theory of planetary motion. In addition, the observations of the sun are compared with Krasinskii's analytic theory AT-1 for the motion of the inner planets (Krasinskii et al., 1978), which is based on radar observation. Corrections are made in the right ascension and declination system for the KF 4 catalog stars, and a reason for the drift in the vernal equinox is suggested.