From: "jimchung2338" <jim_chung@sunshine.net>

Date: March 21, 2009 7:32:06 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Dione Transit of Saturn movie

Seeing again was quite good last night in Toronto so I revisited Saturn for the last time this season I suspect.  There was a timely transit of Dione and Enceladus predicted just after midnight and the closed rings this season make observing them possible.  I began shooting 90s streams just before midnight and for every 15 minutes until I dozed off after 2 AM and woke up at 2:30 with Saturn dipping behind a tree. 

This is a flash movie made in CS2 with 100/1500 frames stacked, aligned and oversharpened to show surface changes better.  You can see Dione (upper left) approaching Saturn and if you review several loops I think you can make out a grey round region that travels across the surface of Saturn at the same level.  My CCD should've been cleaner because several small dust motes contributed to artefactual noise.

http://tech.groups.yahoo.com/group/Astro_IIDC/files/Planetary/Saturnflash.swf

This was a particularly fun experiment and I'd like to try this with my TIS colour ccd for Jupiter this summer.