Hide and Seek with Moons of Saturn

[Ad Astra]

Hello folks,

Out with the Apomax 133mm last night trying to get more of the moons of Saturn! We had great hopes as the sky was much clearer, but the seeing wasn't as good and fine detail was more difficult to detect.

We also found that the turbulence made a big difference in the limiting magnitude and contrast for the evening! Enceladus was easily captured earlier in the week, but last night, both the glare of the rings and turbulent conditions made it invisible to us.

The real treat was Tethys and Dione - both off the western limb of the rings. The pair started the evening very close together - and no one had a hint that there was more than one object at 100x (16mm) or 177x (9mm). But once we had Saturn a little higher off the horizon, we were able to go to 267x (6mm) and the single 'moon' split into two! Over the next hour, the split continued to increase, until we could easily resolve the pair at 100x. Mimas and Enceladus were both too close to the glare of the rings, and this washed them out for us.

I did have a possible detection of Hyperion, but only two of us (we had a party of 6 observing through the evening) were able to spot it at all. There was one other distant object I could not identify - I need to get a chart for Iapetus, I think!

Surface detail was OK, we were able to easily pick up polar region darkening, and some darkening along the Eastern limb as well. There was indication of the large white storm feature (NASA calls it a 'white outbreak' or something like that) below the ring plane, and the Cassini division was fleetingly visible at 277x. We were able to go up to 320x and detect the C-ring, but again, this was a fleeting sight due to turbulence.

I've attached my Saturn observation log sheet if anyone is interested in taking a look.

Dan

Saturn Observation 3-31-11.doc