From: Alan Friedman <alan@greatarrow.com>

Date: March 21, 2009 10:26:33 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Dione Transit of Saturn movie

Great work, Jim!

best,

Alan

On Mar 21, 2009, at 9:32 AM, jimchung2338 wrote:

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.