POSITIONAL DETERMINATION OF A STAR WITH RESPECT TO THE EPHEMERIDES OF URANIAN SATELLITES

This paper presents an observational routine to determine precisely the barycentric positions of the outer planets (Saturn, Uranus, and Neptune) by CCD observations. It is required according to the routine that the CCD observations are obtained with both a long-focus telescope which is used to observe some satellites of an outer planet and a meridian circle which works in a CCD drift scanning manner. Furthermore, the observations obtained with No. 1 CCD on 1-meter te1escope at the Yunnan Observatory is used to determine the positions of two faint stars with respect to the positions of the ephemerdes of Uranian satellites. The results show that the positional precision for each star is comparable to the best observations of Uranian satellites.