1997–2000 CCD astrometric observations of Saturn's satellites and comparison with theories^*

¹ National Time Service Center, The Chinese Academy of Science, PO Box 18, Lintong, Shaanxi 710600, PR China
² United Laboratory for Optical Astrometry, The Chinese Academy of Science, PR China
³ Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK

Corresponding author: R. C. Qiao, rcqiao@ntsc.ac.cn

Received: 18 November 2003
Accepted: 16 April 2004

Abstract

As a continuation of the observing campaign 1994–1996 (Qiao et al. 1999), this paper presents 1167 new measurements of the positions of the major Saturnian satellites obtained using a CCD camera on the 1.56 m reflector at the Sheshan station near Shanghai during the period 1997–2000. The observations include the major satellites exclusive of the faintest satellite, Hyperion. The analytical theory TASS was chosen for astrometric calibration of the CCD and theory computation. Analysis of the data as inter-satellite positions shows that the observations of Tethys, Dione, Rhea, and Iapetus have a standard deviation about the mean of , which matches the accuracy of our earlier observations. However, for a few of the inner satellites, including Mimas, Enceladus, we have obtained poorer residuals up to  to  which we ascribe to lower quantum efficiency of the CCD.