Simple “push-to” telescope system

Over the years, there have been various methods to help astronomers find their way around the skies.

The first is simple – learn the skies.

Many people use setting circles, which is a mechanical method of disks marked with right ascension and declination coordinates, that can be used with star charts to identify areas of the sky. Fitting setting circles to scopes without them is possible, but to use them, you need to set the telescope up fairly precisely, not just plonk it down, as I am prone to do.

A modern innovation is the Go-To scope. A telescope fully fitted with motors on both axes, and a computer control containing a database of items to view. Again, this requires a setup, but this can be done quite easily – point the telescope at a couple of known stars, and the computer will work out the position and exact alignment. After that, when you select an item, the telescope will automatically “go-to” it.

Less expensive, and becoming more common is a “push-to” system. This is like a “go-to” system, but without the motors. Instead a screen on the computer control directs you to manually move the scope in the right direction for the object you wish to view.

Some time ago, I became aware of an Android app called SkEye. This is an astronomy app, somewhat like Google Sky. One of the differences is that although the sky view is by default in the same plane as the Android display (i.e. the sky displayed is that directly behind the screen), with SkEye, it can be optionally configured otherwise, so it doesn’t have to be aligned with the direction you are looking at.

Which means using it as an easy-to-view “push-to” display becomes practical.

My initial experiments, a few months ago, were with my HTC Sensation Phone attached to my 8″ dobsonian with elastic bands. To my amazement, it worked quite well, within the limits of the fixing method.

2013-01-21 18.15.35So I bought a generic phone tripod mount. Breaking the tripod apart to get the screw fitting, I drilled a small hole into the telescope tube, and fixed the mount to the tube, using the screw and some double-sided adhesive tape. Within an hour, it was fixed solid.

I then inserted my phone into the mount, and started SkEye. Simulating use (this was daytime, and indoors, not nighttime and outdoors), I pointed the telescope roughly northwards, and told SkEye I was looking at Polaris. Having configured it thus, I then told it to point to Jupiter, and it did. All I had to do was swing the scope round in the direction indicated, and it should be pointed at Jupiter.

Obviously, I need a clear (and not too cold) night to try it out properly, which will probably not be until the spring. But it seems to work, for the hefty sum of 3 quid. This is cheaper than even the most inexpensive amateur push-to systems, and a lot less than commercial systems. Just how close it gets me to the object I wish to view remains to be seen, but even getting into the right bit of sky is a great help.

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