Authors: Hatanaka Y.
Year: 1995
Title: Photographic observations and improvements of the orbital elements of seven Saturnian satellites. I. Reduction method and results of observations during the 1970 and 1971 oppositions.
Journal: Publications of the National Astronomical Observatory of Japan
Volume: 4
Number: 2
Pages: 23-65
Keywords: Saturn, major, observation, position, photographic, data, analysis
Abstract: Astrometric positions of the seven Saturnian satellites (Iapetus, Hyperion, Titan, Rhea, Dione, Tethys and Enceladus) have been obtained at the National Astronomical Observatory of Japan, Mitaka, during the 1970 and 1971 oppositions. 148 (1970) and 80 (1971) plate exposures have been taken with the 65-cm refractor of which focal length is about 10 m. A new method of plate reduction has been investigated in which a series of plates taken for a few months are connected to construct a chain of plates and Saturn's positions are estimated on the composite plate. The derived Saturnicentric positions of the satellite enables the author to improve its six orbital elements, independently from those of other satellites. The orbital elements of the six satellites (excluding Hyperion) by G. Struve and those of Hyperion by J. Woltjer have been adopted to be improved. Improved values for each opposition have been determined by the method of least squares. The standard errors of (O-C) values for the satellite's position before the improvement and after that are 1?26>0?10 (1970) and 1?11>0?13 (1971) for Iapetus, 0?95>0?30 and 1?12>0?25 for Hyperion, 0?17>0?12 and 0?19>0?10 for Titan, 0?12>0?09 and 0?17>0?07 for Rhea, 0?17>0?15 and 0?19>0?14 for Dione, 0?18>0?14 and 0?14>0?09 for Tethys, and 0?22>0?21 and 0?31>0?25 for Enceladus.
Bibliogaphic Code: 1995PNAOJ...4...23H

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