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Stargazing anew

6 March 2009

Sky-Watcher Skymax 127 SupaTrakAfter much consideration, and with my upcoming studies in mind (or at least that’s how I justified it to the accountant part of my brain), I bought a telescope earlier this week and it was delivered yesterday. I spent a few evenings considering my main options – refractor, Newtonian, Maksutov, Schmidt-Cassegrain, or Dobsonian-mount Newtonian – and speaking with various people, I whittled the choices down to either Sky-Watcher’s Explorer 130P or Skymax 127 (both with SupaTrak motorised mount). While there are undoubtedly better telescopes on there in this aperture range (the number refers to aperture in mm), this shortlist came about due to reviews given, price, and availability. Both have received excellent reviews, and they’re readily available.

The Explorer is a Newtonian, so is considered fine for general astronomical observation due to its aperture and field of view, and the Skymax is a Maksutov, so is considered ideal for up-close examination of objects. As I understand it, the reasons for the distinction are based upon:

  • Size of the primary mirror. The Newtonian is 130mm and the Maksutov is 127mm, so both roughly 5″.
  • Amount of light reaching the primary mirror. The Maksutov has quite a large secondary mirror and corrector plate (meniscus lens) which together reduce the amount of incoming light more than the Newtonian’s relatively small secondary mirror.
  • Focal length of the telescope. The Newtonian is 650mm and the Maksutov is 1,500mm, due to the way the mirrors fold the incoming light to the eyepiece.
  • Focal ratio (focal length divided by mirror size) will be familiar to all photographers as f-stop (to control depth of field). The Newtonian is f/5 and the Maksutov is f/11.8. The higher the focal ratio, the narrow the field of view.

A Newtonian has a wide FOV that allows it to naturally see a wide area of the sky, meaning it can fit a large nebula or a planet quite easily, but will need additional magnification to look closer; whereas a Maksutov has naturally high power but a narrow FOV, meaning it might not be able to view all of the largest nebulae at once, but is superb at picking out detail on what it can see. However, after discussing the matter with a number of amateur astronomers, it seems that at this level (aperture and price), the distinction is really not an issue.So… I bought the Skymax 127 (pictured).

I think I’ve got all that right. If not, please let me know.

It’s probably worth saying at this point that I’ve made enquiries with my local astronomical society, and plan to go along to their next meeting with a view to joining. With a topic like astronomy, you really can’t beat being part of a skilled community, learning from them and participating in their activities (including dark sky site nights/weekends).

The telescope was delivered to my workplace yesterday, though I had to wait until I got home before I could unwrap it. And that was the first thing I did when I walked in the door – opened the Russian dolls (it was a number of boxes within a box within a box within a box – no kidding), made sure everything was there, read as little of the documentation that I could get away with, and set up shop on my front porch. I hadn’t aligned the finder-scope, didn’t level the tripod (it has an inbuilt bubble level), and only performed a cursory zeroing of the motor mechanism, so I wasn’t going to get a quality experience, but I just wanted to look through it already!

Venus was still ~10° above the horizon, so I lined up on that first and was pleased when the bright, crescent sliver appeared in the telescope. It works! And it was the first time I’d look in a telescope in about 20 years – I was both immensely excited and disappointed with myself for letting it happen. I’d always intended to replace the 5″ Newtonian I’d inherited when my great-uncle had died, and then subsequently sold as other life issues took priority (though I did enjoy watching Halley’s Comet through it during its last pass), but somehow that never happened. Still, all that’s under the bridge now…

Next was the Moon, almost directly overhead and half-full. When it came into view in the eyepiece I just gasped. I’d forgotten how beautiful and inspiring it was. It’d had that effect on me since I first looked into a telescope at age 6 or 7, and 30 years later it does exactly the same thing. I set the controller up to track it (which it did, but required frequent corrections because of my lack of setup) and gazed at it in open-mouthed awe for a good 30 minutes. I never get tired of it.

Feeling I had the solar system sorted, I thought I’d try out Orion as it has a number of stars and magnificent nebulae to choose from, all in one small chunk of the celestial sphere. However, as I’d not aligned the finder-scope or zeroed the tracking system, it made finding and keeping anything worthwhile quite hit-and-miss. So rather than spoil an otherwise great time, I swung it round onto Sirius (or Dog Star, due to its location in Canis Major) and enjoyed the light show of the brightest star in the night sky.

It was while out watching the sky that I saw the steady stream of visitors into my neighbour’s house, who holds a loud prayer evening every Thursday for the evangelical church of which he is a vocal, proselytising member, and was quite pleased that their comments and brief conversations with me all remained natural. Normally it goes very differently — though one did have to ask the other if he’d brought “his weapon” along, to which the other asked whether he should use the KJV or NRSV “weapon”…

So after 90 minutes of a marvellous stargazing experience, I packed up and brought everything back inside as it was quite cold, I don’t yet have a dew shield and the unit wasn’t setup correctly. Once I’ve aligned the finder-scope and learned how to correctly zero and adjust the controller, I’ll go back out and try again on Orion.

Orion and the Southern Cross were my favourite constellations as a child growing up in Australia, and Orion remains so today particularly because it’s visible in either hemisphere and remains a friend from a simpler time, reminding me of childhood wonder.

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