The moons of Saturn

I was looking back over last year’s images and discovered I’d managed to reveal the Saturnian moons Mimas and Hyperion. Admittedly, Hyperion, a porous moon full of deep holes is hard to see, but is one of the blobs of ‘noise’. I had to chop off Iapetus, which was clearly seen, along with a 13th magnitude star, way out to the right. This view was obtained at 2250UT on 10 May 2010. From left to right you have: Titan, Rhea, Dione with Hyperion pretty close to its lower left, Saturn, Mimas, Enceladus. Tethys was behind the planet at this time. The shallow ring angle and reasonable seeing helped pick out these tiny moons. This brings my Saturnian moon total to 9. The outer moon, Phoebe, on an earlier image, is now thought to have produced a huge outer ring causing Iapetus’s dark side. Mimas is an amazing object, with a huge crater like the death star, and it causes the Cassini division in the rings.

Planets!

We have a good range of planets up at the moment. I trained the recently collimated 235mm Celestron on all of them. I used a -5D Barlow I found lying around and took a few snaps of each planet on my Canon EOS 350D through it, giving a focal length of about 4.5m at f/20. Exposure bracketing was done and I stacked the best few images of each planet. After contrast enhancements and aligning the red, green and blue channels etc., I put all 4 together to compare size for size & colour for colour. I worked my way round the sky from twilight to opposition, i.e. in order of increasing Right Ascension hour. Then I checked out the view of Saturn. Very sharp! I saw a very interesting alignment of moons next to the rings (Monday 12th April), so checked it out on the 20". This was brighter, but fuzzier. I attempted to image the moons but the tracking / vibration wasn't good enough on either scope. Shame - there were four moons above 12th magnitude within about 3 arc seconds.