CCD astrometric observations of the five major Uranian satellites made in 1998–2007 and comparison with theory★

Abstract

An observational campaign of the five Uranian major satellites was carried out during the period 1998–2007. A total of 2358 satellite observations in 1025 CCD frames were taken at two observational stations near Beijing and Shanghai with two telescopes of 0.8 and 1.56 m diameter. The observed positions were compared to the two Uranian satellites’ recent ephemerides GUST06 and LA06. The result of this comparison has shown that the accuracy of our observations is about 100 mas for all the satellites. The satellite theories GUST06 and LA06 appear to be quite reliable for the first four satellites, with an accuracy of about 50 mas, but for Miranda the accuracy is only about 200 mas. Moreover, we have found a systematic error between the two planetary ephemerides DE405 and DE421 of about 80 mas for the period of our observations.