Saturn w/ New 8" F7 Planetary Newtonian

Name: Curt Diggs
Observing Site: Home (near Dallas, GA)
Observing Date: 2/18/07
Observing Time: 9:00 pm to 10:30 pm
Seeing: 7
Transparency: 8
Equipment: Home built 8" F7 Planetary Newtonian on GEM mount

Seeing was good to excellent with slight to moderate atmospheric turbulence. The transparency was excellent.

I spent about an hour observing Saturn at various powers to get an idea of this new scope's limits and capabilities as a planetary-type scope. The mounting is inadequate (an older GEM from an 8" SCT on a home-built pedestal base) and previous attempts had been frustrated by wind-caused vibration. This evening was relatively still so I was able to get long periods of
observation with a steady image.

Saturn's rings were easily resolved at even the lowest powers (55x) and the Cassini division became resolvable at around 100x. The highest power I can get currently with my eyepieces and Barlow combination is 300x. This proved to be too much magnification and turbulence seriously disturbed the image (turbulence is magnified right along with the image under observation). The ideal power turned out to be 200x which was achieved by using the 14mm ED and a 2x Barlow.

I set my observing stool up and was able to spend long minutes at the eyepiece in a relatively relaxed and unstrained position. I believe this contributes significantly to the ability to pull the finer details out.

Although Cassini's division was almost always resolved and clear, finer planetary details would go in and out as the atmospheric turbulence came and went. Over the course of about an hour, I got several 5 to 10 second periods when the turbulence almost completely stopped. The views of Saturn during those brief periods made the long waits between them totally worthwhile.

I hate to use the (overused) term "Hubblesque" to describe the images but that thought passed through my head as the image cleared and much of the subtle detail seen in Hubble photographs of Saturn popped out. The crepe ring began very obvious which I had seen before but had never seen the color (reddish brown) and the fine demarcation lines in the set of rings just outward from the crepe ring. These were only visible for a few seconds but were unmistakeable.

All in all, I'm very pleased with the operation of the new scope except for the mounting. The old GEM is just not up to the long F7 tube so a new, sturdier mount is under construction.