Telescopy

My Darling Suyin has given me a telescope for Christmas, and what a fun toy it is. It’s an Edmund Scientific Astroscan, a very simple and easy to use telescope that’s been in production for ages and is generally well regarded. She’d obviously noticed how many times I’d read this review on Dan’s Data. Smart girl.






It may look funky, but inside that groovy casing is a fairly conventional 102mm (4.25”) Newtonian reflector telescope. This type of scope, which utilises a paraboloid mirror, has a lot going for it so not surprisingly there are a lot of them around. I’m not sure there are a huge number of Astroscans in Australia though, given that until recently the manufacturer didn’t want to sell them overseas, or to distributors who would. This was all too hard for me, but Suyin persisted, tracking down another site, Ward’s Natural Science that did. She even negotiated down the usually ridiculous shipping charges from the U.S. Hooray!

Of course it rained for a week or so after I got it. Not unexpected.

When it did finally clear I had my first ever chance to play with a non-rubbish telescope. First target was the moon, which was quite spectacular. All the main features, big craters, seas etc were very clear, especially around the edge of the shadow (it was gibbous, which is nothing to do with gibbons but was a few days after the full moon). I even tried a few photos, which came out surprisingly well.





The ball and socket type mounting used is not designed for astrophotography as it cannot track celestial objects for long exposures, like a powered equatorial mount can. It’s still possible to take photos of bright objects like the moon or maybe planets using the sophisticated technique of holding the camera up to the eyepiece. I used a tripod mostly, but it was a bit of a juggle to get it lined up, manually focus, set aperture and shutter speed (auto settings don’t work well) and try to get a photo before the moon wandered out of frame.

A few days later I got a chance to try again, and few slightly better shots.





Also on the agenda was looking for planets and the first likely-looking candidate turned out to be Saturn! Seeing Saturn’s rings for the first time was pretty thrilling, although it’s still quite small using the 15mm eyepiece (30x magnification). My best photo doesn’t do it justice so I’ll try again next time. I’m also on the lookout for a good 6 - 8mm orthoscopic eyepiece, which will boost magnification to about as high as this scope will go.




I found Mars too, although it was too distant and small to see any detail on. A bit later I spotted a suspiciously planet-like object rising which turned out to be Jupiter. While the banding wasn't visible at this magnification I could see the disk and four moons all in a row. Very cool..

The Orion Nebula was visible but thanks to the large amount of light pollution here in Sydney (not helped by the streetlight that blasts into our backyard) it wasn’t much more than a faint cloudiness. Looks like we'll have to start planning an overnight trip to somewhere dark... More pics to come.

So, if you're looking at purchasing a telescope there are a number of very useful articles on selecting one. The common theme is "Don't buy a Department Store telescope (or a cheap one on Ebay) as they are rubbish". While not the largest of amateur telescopes (or even a medium sized one) the Astroscan is approximately one billion times better than those crappy ones. As a bonus, it does not require its own observatory dome (not that I wouldn't mind one)..