Saturn in the 2008/2009 apparition: Part II

2018 September 21

Mike Foulkes

Introduction
During this apparition, the rings were edge-on to the Sun and Earth on 2009 Aug 11 and Sep 4 respectively.  One benefit of the low ring inclination was that glare around the planet was reduced. This made the detection of the inner satellites by visual and imaging means much easier, particularly for Enceladus and Mimas.
The satellites from Titan inwards orbit the planet close to the plane of the rings. Consequently with the low ring inclination, the satellites appeared in approximate line with the rings during this apparition as shown in Figure 21. [Numbering of Figures, tables and references in this paper continues consecutively from Part I.] Sometimes the satellites were detected very close to the planet, either to the north or to the south of the rings (e.g. Figure 16(c), Part I).
On 2009 March 2, Gray observed both Titan and Ceres under very good conditions in an attempt to resolve their respective disks with his large aperture Dall-Kirkham Cassegrain. The disk of Ceres was approximately 0.8″ on this date. Gray noted that he conditioned his eyes by initially observing the close double star 54 Leonis. Using a binocular viewer, the disks of both Ceres and Titan appeared non-stellar using x365 and were unmistakable at x535. At this magnification, he thought the disk of Titan looked soft-edged (see Figure 22).

Transits and eclipses
Satellite and shadow transits, occultations and eclipses of Titan inwards to Mimas occurred during this apparition. However with amateur instruments, transits were only observed for Titan, Rhea, Dione and Tethys and their respective shadows. A shadow transit of Enceladus and possibly Enceladus itself was also observed. Eclipse entry and re-appearance were only observed for Titan and no occultations were recorded. (continued…)

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