Completion of the FK5 Extension and a Preliminary Investigation of the FK5 System

Abstract

The construction of the Fifth Fundamental Catalogue (FK5) is shortly described with emphasis on the system of the Basic FK5 and on the completion of the FK5 Extension. New observations have revealed systematic errors mainly in the declination system of the FK5 and in the right ascensions south of −50°. Comparisons of the new observations with the Basic FK5 and the FK5 Extension (made separately for the bright and faint stars) have shown that the FK5 Extension is essentially on the system of the Basic FK5.