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Assesment of the Project Star telescope June 18, 2008

Posted by aquillam in Astronomy.
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Last night, I had some time and it was clear (an unusual concurrence lately) so I took my Project Star ‘scope outside and looked up. Anyone who has used the project star ‘scope already knows what I’m about to say.

The ‘scope is increadably hard to point. The field of view is so small that it’s nearly impossible to scan around the sky and find anything. Siting down the tube doesn’t work very well either because it’s impossible to hold the ‘scope still while you move your eye back and forth from the eyepiece to the tube. I did get a tip on a “mount” for this ‘scope at the IYA conferece, from the Hands-On Optics folks. Fill a rubber glove with sand, making sure to fill the thumb and forefinger. Tie off the wrist. Set the glove down with the thumb and forefinger up. Place ‘scope between the thumb and forefinger. Unfortunatly, this doesn’t work very well for objects that are high up, like most of the sky…
Once it’s pointed, it’s almost impossible to hold still enough to keep your object in the field of view.
Focusing is difficult, especially if you’re trying to look at something small, like a star.
The image is dim. The dimmest objects I was able to view were the stars in the big dipper. In other words, the limiting magnitude was around 2. There were objects I could see naked eye that I could not pull in throught the ‘scope
Chromatic aberration is apparent in all images.

The moon was the easiest target, but it does not gain significant depth except right along the terminator. This was true even when I looked last week, at quarter phase.
Arcturus did look red.
Vega did not look blue (but then, it doesn’t usually look very blue to me).
Mars looked a lot like Arcturus, but dimmer.
Saturn looked like I needed to clean my glasses. While I could not get it to look point-like (like a star), I also could not tell that it was any different from Mars, except it was brighter and yellowish.
Alcor & Mizar were resolved, but not the star in between.
I am doing these observations in light polluted and somewhat cloudy skies. I’d estimate the naked eye limiting magnitude at around 3.4 last night, based on the stars visible in Leo.

I’ve also used friends and co-workers of friends as guinea pigs for these ‘scopes.
They make a very good demonstration of how a telescope works, even how the lenses have to be oriented.
They are fine as terrestrial ‘scopes, especially if you can prop them on something (the rubber glove mount should work well for terrestrial viewing)
People enjoy being able to play with them, especially seeing what happens if you put the lenses in backwards, or look the wrong way.
They are ok for looking at the Moon.
In short, they make a great teaching tool, but they are NOT a replacement for a real telescope In fact, I’d put them right up there with the department store 60mm ‘scopes, except that these aren’t overpriced.

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