h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I am very interested in star-gazing and would like to buy a telescope. I would like to know which one should I buy for a beginner astronomer. I would like to get a telescope that is light and portable.

Thank you

Sorry, the one that I bought some 35 years ago was given to a Scout Troup a few years later . . . Gnomon would be a good chap to ask though.

As someone who has owned two "beginners" telescopes, I offer this:

First - what are you trying to see? If all you want to do is roam around the sky looking at random stuff, see Jupiter's moons, the rings of Saturn and some startling detail on the surface of the moon, then all you need is a cheap scope from a catalogue shop. There's just no need to spend hundreds and hundreds of pounds on a dual-motor-driven computerised thing if all you're doing is a bit of hobbyist stargazing. Spend no more than £150 if buying brand new. You can probably pick up something acceptable off ebay for less than £50.

The counter-intuitive secret is that the most important part of the package in terms of its impact on your experience is NOT the telescope; it is the mount on which it sits - the thing between the tripod and the scope which allows you to adjust where it's pointing. A novice might naively think that it wouldn't matter - you just point the thing at what you want to look at, and look, right? WRONG. Any decent telescope will have a very restricted field of view, i.e. what you see through it will be a very small patch of sky. Even if you can successfully point your telescope at your object of interest (and that's not as easy as it sounds), that object will move across the sky and out of your field of view in a matter of *seconds*. It is therefore vitally important to have a mount that allows you to follow the object simply and smoothly.

There are two types of mount: the "equatorial" mount and the "alt/azimuth". The "alt/azimuth" mount is simple, doesn't require any setting up, and is easy to understand. It is also worse than useless. It allows you rotate the telescope around a vertical axis (azimuth) and around a horizontal axis (altitude), much like a conventional camera tripod. This would work well only if your telescope was located at the north or south pole, where the celestial sphere is (apparently) rotating around a point directly above you. Anywhere else, following an object across the sky requires you to adjust TWO settings at once. Good luck with that.

An equatorial mount is slightly more complex and requires some setting up (once, for any given location, e.g. your garden), and is slightly harder to understand. Only slightly though. It allows you to set an angle (the polar alignment), which once set, rotates the scope around the sky by adjusting just one control - smoothly turning a wheel as you look into the eyepiece keeps your object in sight. You can even fit a motor to some mounts so you don't need to bother doing that, but that's probably too far for the beginner. It does make tracking stars and planets simple and easy, once you've found them. With a little more setting up, it makes finding them in the first place easier too. If money is no object, there are mounts that will find objects for you - you set them up, tell them what you want to look at, and a small computer points the scope at the right bit of sky automatically. Cheating, I call that, but if you're prepared to drop not far short of a grand on an instrument, it'll do the hard work for you.

DO NOT BUY ANYTHING WITH AN ALT-AZIMUTH MOUNT.

For instance: this thing looks good, right? http://www.argos.co.uk/product/5067718
Wrong. The scope is probably quite good (for a cheapo). The mount will make you want to put it in the bin. Avoid. Similarly this, much cheaper scope is probably OK, but the "Dobsonian" mount is just alt-azimuth by another name. http://www.argos.co.uk/product/6998460. Avoid.

The next question is: refractor or reflector? Which is to say, lenses or mirrors? Which is to say, long thing you look down the end of, or stubby thing you look in the side of? Lenses are harder to manufacture than mirrors for a given size, but give a better quality image. For value for money for the beginner, you're better off with a reflector. They're also lighter.

This thing is probably worth a look: https://www.jessops.com/p/skywatcher/explorer-130-eq2-telescope-89841

It's a reflector with a non-motorised equatorial mount (although you can fit a motor to it later).

If money's no object, there's this: https://www.jessops.com/p/celestron/nexstar-6se-computerised-telescope-93575
There's also essentially the same gadget with a bigger eight inch mirror for another four hundred quid.

Check ebay or even Freecycle, though - a LOT of people buy beginner scopes, look at Saturn, Jupiter, the Moon and a few stars and go "huh" and into the attic they go, eventually to passed on.

Seriously, though - EVEN IF IT IS FREE, don't get an alt-azimuth mount. You have been warned!

Good advice.

Several years ago, I bought a cheap but quite decent short tube reflector like this one.

http://www.telescope.com/Telescopes/Beginner-Telescopes/Orion-SpaceProbe-130ST-EQ-Reflector-Telescope-Kit/pc/-1/c/1/sc/21/p/116309.uts

But living so near the Houston metropolis and all it's pollution, light and smog, rather dampens the experience. I gave it to a friend's teen daughter after it sat in the closet for a couple of years. I got a pair of astronomical binoculars now that are fine for viewing the occasional high visibility thing like comets and whatnot.

And I wouldn't mind having an equitorial mount for it. Hoovooloo is absolutely correct about how mostly useless they are for sky gazing.

h2g2 has a couple of entries that may be helpful:

A827309 How to Choose an Astronomical Telescope
A87874898 Choosing an Eyepiece for an Astronomical Telescope

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Thank you all for very helpful advice. I have been fascinated and deeply interested in Astronomy since I was a child of 5 years of age.

My hubby is a keen amateur astronomer. He always says a good pair of binoculars is better than a small telescope.
If handheld, 10x is about max usable. Something like 10x50 would be good. If using a support you could go up to 20x80 or so.

Thanks Teasewell that's a great idea and the binoculars could double up for star gazing and bird watching.