Polar scope woes, Stellarium telescope control and 1st light 2010

Posted by XTSee on 30th January , 2010

Last night/morning (Jan 29th/30th) was the first time I have been out with my C6-SGT not only for 2010, but also for a whole year (previous post explains about my pond building antics putting my astronomy on hold!).

Coming home from work the evening sky was beautifully clear, and I was in a great mood taking my dog Ben for his walk across the fields, listening to the brilliant Anjunadeep01 by Above&Beyond nice and loud on my iPod.

Earlier at work my astro mate James had showed me an article about the Moon, Mars and The Beehive Cluster in Cancer being nicely grouped, with Mars at opposition (closest/brightest, yet light takes 9 minutes to get to us!), and a Blue Moon (largest apparent diameter) and M44 in Cancer, (which is my star-sign), so in all a nice grouping to observe! (And another article about Moon, Mars and M44 Beehive Cluster).

Polar Frustrations

This was also the first chance for me to try out a new polar alignment scope I had been given (in return for a favour) for my EQ5+SynScan Goto upgrade (like a CG-5) german equatorial mount - but no instructions!

The main problem was that it took me an absolute age to get used to everything again, and despite taking it easy with the idea of understanding the polar scope and how to install and align it properly, it just did my head in!

Its difficult to see through it to make out Polaris and the surrounding stars, and I wasn’t sure whether it was screwed in the correct amount because the constellation markings for Cassiopeia and Ursa Major seemed on the wrong sides even when I rotated the mount about the Right Ascension axis (there are onstructions on my mount which prevent full rotation). So I was constantly taking the polar scope out, taking it indoors to see if there was some way of rotating the markings reticule independently of the body. Then I undid the 3 little hex screws of the collimation whilst it was in the mount, and I heard the reticule drop down inside the body of the scope! Hmmm. Thats screwed it for tonight. How the hell are you supposed to do this?

There are also markings for Octans on the reticule in the polar scope which I then thought was another star near Polaris that I was supposed to rotate the mount to align with. So some Googling revealed that was intended for use when you live in the Southern hemisphere, and use the constellation of Octans to align with, so this caused me yet more confusion.

After two hours frustration in the freezing cold (snow is forecast later tonight) I decided to just polar align by eye/hand through the mount without the polar scope installed, which has been perfectly adequate for casual observation on previous occasions, and I wanted to get on and observe properly.

On a positive note I found two useful things, this page by Carsten Arnholm at http://arnholm.org/astro/ on telescope polar alignment, which also contains a link to a nice little utility called PolarFinder.exe created by Jason Dale which shows you how to align the view through your polar scope at different times of the night. Check it out.

Dew Controller

At the start of the session I had plugged in my new dew controller band and control box which I had built myself, and this was again the first opportunity I’d had to try it out. Well there is no dewing up of the front glass on the telescope, but also tonight is quite a cold dry night, so perhaps not a real test of how effective it might be.

Stellarium Telescope Control

The next thing I wanted to try was controlling the Goto function of the CG-5 using my laptop with the Stellarium astronomy software installed. This requires the latest Ascom drivers together with a utility called Stellarium Scope

With these configured (some settings must be made, and serial cable plugged in via USB/Serial converter adaptor), it is simply a case of starting Stellarium Scope and connecting to the telescope, then selecting an object to view, then press CTRL-1 to slew the scope to the object. A crosshair target also appears on the Stellarium screen to indicate where the telescope is currently pointing. Oddly sometimes it gives a blue message box saying “Already slewing”, but pressing CTRL-1 a second time has the desired effect. Pressing CTRL-2 will “sync” Stellarium currently selected object to the current pointing position of the telescope mount hardware, and CTRL-3 is emergency stop slew.

I like it, and I’m very impressed by this control in a free piece of software. Stellarium just looks so nice and is very easy to use, whereas Carte du Ciel (also free, and with telescope control) I can never remember how to use it.


By now its 1am, and time to get a hot coffee, some whisky, my ski-jacket, and Ben dogs bed/blanket so he’s a bit warmer on the ground (he refuses to stay indoors when I’m outside).

With the telescope under control of the laptop, I slew round to Mars to get a view, and see its disc. With the Moon so close there is a lot of glare, and the background¬† is a pale bluey grey. I can only just make out markings on Mars, and although its Moons shoud be within the field of view, they are not visible. I try a variety of eyepieces, including my Hyperion 13mm + tuning rings + 2xBarlow which gives the maximum magnification I can achieve. Its ok, but not great. Perhaps if my SPC900NC webcam wasn’t in bits (I’m trying the Steve Chambers mod for long exposure), I might be able to get some imaging to reveal more.

Likewise the Beehive cluster, normally a beautiful cluster of diamonds, are fine pin-pricks against an even more washed out lighter background as this is much closer to the moon.

The Moon itself is blinding, so after installing a moon filter to make it more comfortable I slowly scan the surface and edges taking in the view. I love the fine control using the CG-5 handset to move the scope. My XT10i dob is fantastic for bright clear views, but it can be a bit unwieldy sometimes when trying to make fine pointing adjustments. Even the moon is a little disappointing when this bright and full - there is little contrast, no terminator to give shadows.

And finally my dew controller drains the battery to the point where the Goto fails to slew properly, drawing the session to a close at 2.30am.

Well probably not the greatest first light for 2010, and perhaps in retrospect I would have got a nicer wide-field view with my 20×80 binos, but enjoyable nonetheless for learning new things and getting back into the swing of things.

It was nice to think of poor little robot explorer Spirit up there on Mars surface, stuck fast in the sand with only 4 of his wheels working, yet despite this he is still to be used as a stationery observatory to track wobbles in Mars orbit, and dig deeper in the soil around him. I think its 6 years he’s worked now, when planned for just 3 months originally, what an amazing achievement. Well done NASA.

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8 Responses to “Polar scope woes, Stellarium telescope control and 1st light 2010”

  1. Office Supplies (1 comments)

    This sounds like a wonderful piece of equipment, if you can get to grips with how it works and how to set it up. It would be something that I would love to show my children, especially my daughter who is really interested in astronomy.

  2. Webdevelopment (1 comments)

    Great story! I’ve used different telescopes in the past, but none seem to be of a quality high enough to get some clear views of the sky. So the C6-SGT is pretty good, according to you?

    I would love to know what I should buy, to be honest. It doesn’t matter if it’s really expensive or not. Thanks for your reply!

  3. Funny Guy (1 comments)

    Wow the C6-SGT looks like a decent bit of equipment, might have to invest in that.

    Great post, keep em coming.

  4. Remote Online Backup Solutions (1 comments)

    I would love to look at the stars and the constellation. I love astronomy but I haven’t had any chance looking through a telescope. Your equipment is awesome, hope I have one like it.

  5. David (1 comments)

    Love this site, good job.

  6. Toshiba Satellite Battery (1 comments)

    This is really cool. I love looking at this sort of stuff and I’m definately going to put your pic at the top as my background on my Toshiba Satellite Laptop…if my battery doesn’t die in the process. Good luck and keep your eyes to the sky.

  7. Palletizing Robots (2 comments)

    Nice story. I always like typing out my days onto my blog, than a diary. Typing always makes me think faster and I’m able to spit out more thoughts :p Do you take any snap shots of the stars?

  8. Kushked (1 comments)

    I wouldn’t do a 3-star alignment THEN connect to Stellarium. Rather, I would do all the alignment and synchronisation through the software, not the handset. If you are controlling the mount via the laptop and EQMOD you don’t need the handset alignment.

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