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Old 31-01-2008, 10:27 AM
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edwardsdj (Doug)
Doug Edwards

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Join Date: Sep 2007
Location: Brisbane
Posts: 677
Hi Scooter,

You seem to be doing things better now. It's not like watching TV. It takes time and practice to see details on planets. I must confess that I haven't looked seriously at Saturn visually this apparition yet as on the few evenings when the clouds have shifted I've been taking images.

As I've been saying, quoting magnifications doesn't make a lot of sense with images. Image scale makes sense.

The view you show looks like the sort of thing you would see in a Plossl eyepiece at 250x to me. The CCD chip in my webcam is tiny so the planet takes up a lot of it. It's also a lot harder to get the planet onto the CCD than to get it into an eyepiece.

Lengths in the sky are measured in angles. From the horizon to the zenith is 90 degrees. An arc minute is 1/60 of a degree. An arc second is 1/60 of an arc minute or 1/3600 of a degree.

The Sun and Moon have a diameter of about half a degree or 30 arc minutes. Saturn at opposition has a diameter of about 25 arc seconds. Jupiter gets to around 50 arc seconds.

Midnight to 1am is an optimal time to view Saturn at the moment. Sounds like you're getting the hang of tracking with the Dob now too. I'd try to see as much as I can at 166x first. 250x will only be possible with good seeing.

I'll just point out some things to look for (in rough order of difficulty):

How many of Saturn's moons can you see?

Can you make out the Cassini division?

Can you see the shadow of the rings on the planet?

Can you see the shadow of the planet on the rings?

Can you see the crepe ring?

Can you see a band on the planet?

Hope this helps, and keep observing. Saturn is a very rewarding target!

Have fun,
Doug
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