How To Select Beginner Astronomy Targets

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Introduction

I often encounter newcomers to astronomy who were disappointed with their first couple of attempts to observe. In discussing their experiences, I've come to realize there are two major reasons this happens: poor preparation of the equipment and poor choice of the first few objects to look at. Another article is about equipment preparation; this one discusses good beginner objects.

Click here if you want to skip my philosophical rambling and just see the list of recommended objects.

If you are a typical beginner without an experienced astro-buddy at your side, you will probably get out your new telescope, hopefully set it up and align it fairly well, and then look at the moon. After the moon, you will ask yourself "what else shall I look at?", and the answer you come up with is often a bad one. Beginners tend to select, for their first targets, objects that are famous, or objects they've seen spectacular photographs of in astronomy magazines or on the Internet.

When I made this mistake, I tried to start on the Andromeda Galaxy, M31, because I "knew all about it", and had seen spectacular images of it. Mars is another common disappointment for beginners. So are individual, well-known, stars (e.g. "the North Star") and constellations ("I want to look at The Big Dipper in my telescope.") These are all bad ideas that will lead to disappointment.

In fact, it seems that most astronomical objects that typical beginners have heard of (except the Moon and the two large planets) are bad choices as first targets.

What Makes a Poor Beginner Object?

Why do I now think the Andromeda Galaxy was a poor place to start? Why do I think Mars is a poor choice? There are several things that make an object a poor choice for beginners:

Too Large

Telescopes show a very small portion of the sky - typically the size of the full moon or smaller, possibly much smaller. Looking at constellations in a telescope, therefore, makes no sense - they are far too large to fit in the field of view.

Even certain objects that I consider to be good choices - such as the famous "double cluster" - are quite large and may not fit in the field of view of some telescopes. The mid-sized 200 - 280 mm (8"-11") Schmidt-Cassegrain Telescopes (SCTs) that are so popular with beginners tend to have very long focal lengths, and may be too powerful to show very large objects in their entirety without investing in ultra-wide-field eyepieces.

M31, the Andromeda Galaxy, was too large to be my first target for my SCT. (In my list of recommended objects, I specifically point out the three or four that are very large and may be problematic for certain telescopes.)

Hard to Find

Some objects are easy to find because they are visible with the naked eye or are close to something that is. Other objects are quite difficult to find. Experienced astronomers enjoy the challenge of the hunt; beginners will be frustrated that they can't simply "point the telescope where the star chart says" and find the object in their eyepiece. (The list of objects I recommend below contains only objects that I can find easily, with a small telescope and no electronic assistance, and most of them can be found in a moderately light-polluted suburb.)

Not Interesting in a Small Telescope

Some objects are simply not well-suited to the small telescopes used by most beginners. Galaxies are an example: small telescopes don't gather enough light to make them visible. Mars is another example: a small telescope doesn't have enough resolving power to allow any details to be seen - the beginner sees "just an orange dot".

Stars, as another case, are generally not interesting in any telescope. They are so far away that they are just points of light. Collections of stars - double stars and star clusters - are very interesting, but individual stars will generally receive a reaction of "so what?".

Looks Nothing Like Expectations

Astro-photographs are the source of much beginner disappointment. The beautiful structure and colour of galaxies that you have seen in photographs is not what you see at the eyepiece (why?). Those images require enormous investments of time and money, and specialized equipment. If you choose one of those objects as your first target, you may be disappointed. Later, when you are more experienced, you will chase such targets and be impressed that you can see them at all.

M31 was a disappointing choice as my first target: I was expecting spiral arms and colours, not a dim fuzzy patch. (Later I learned to be impressed by the fuzzy patch, by realizing what I was seeing.)

(In my list of recommended objects, I omit the colour CCD photos, and include images - usually simulations - of what you can expect the objects to look like in a small amateur telescope.)

Not Conveniently Timed or Located

The sky moves, with the time of night and the season. You need to set out to see objects that are actually visible at that time of year, at a reasonable time of night, and in a part of the sky to which you have a clear line of sight.

(I recall a Girl Guide leader who asked for a demonstration to their club. They wanted to see Saturn, at about 7:30 on a particular weeknight in July. I had to explain that (a) Saturn wasn't visible at that time of year; and (b) it wasn't dark at 7:30 in July. We gave them an indoor slide presentation, and returned the following February to show the girls the planet.) (The list of recommended objects below is restricted to objects that are visible one or two hours after sunset.)

What Makes a Good Beginner Object?

Good beginner objects, then, would avoid the problems above. I suggest the following criteria:

Easy to Find

It is my experience, from many public outreach sessions, that beginners want to look at objects, not look for objects. Beginner objects should be easy to find: either visible with the naked eye, so you can just point the telescope at them directly, or conveniently located relative to visible objects, so you can experience seeing something in the telescope that you can't see with the naked eye.

What about computerized go-to telescopes? Go-to scopes are controversial in online forums. Personally I like them and think they have excellent uses. But eliminating the requirement that beginners learn how to find things isn't one of them: as a beginner, you need to start with easy-to-find objects. The expectation that you can take a low-priced go-to telescope out of the box and effortlessly find interesting objects is unreasonable and leads to disappointment. In beginner discussion forums, you'll notice that more questions are about getting the electronics to work than about observing.

Observers without go-to scopes find objects by a technique called star-hopping: finding a nearby known object, then using it as a reference to find another nearyby object, and so on, making a series of planned hops leading to the expected location of the target object. This is an excellent technique to learn - you will enjoy the hunt, and you won't be lost on the evening something fails in your go-to circuits. However, I think star-hopping is also a lot to ask of the absolute beginner on their first night out. It assumes a good map, the ability to estimate angles in the sky, and good familiarity with the (possibly reversed or inverted) directions that things move in the finder scope and main scope. Excellent beginner objects are easy to find with one point of the telescope - so I recommend objects whose location instructions are simple, such as "exactly halfway between these two easy-to-see stars".

Impressive and Interesting

Your first experience with your telescope should be an excellent one, to secure a place for this wonderful hobby in your mind. Beginner objects should be visually impressive - so your first reaction is "wow!" - or interesting and thought-provoking, or both. We want to avoid the "I paid $500 for this?" reaction. It takes a long time to recover from that.

Visual Appearance Similar to Expectations

Galaxies look so different at the eyepiece than in the photos you've seen that you may be disappointed. Good beginner objects either look somewhat like you expect, or are so unfamiliar that you have no expectations.

Convenient Location and Timing

Good beginner objects don't make you too uncomfortable. You should select objects that are located at a reasonable height above the horizon (not so low that trees interfere, not straight up and awkward) just after it gets really dark. This means that the choice of beginner object will vary with the season and your location, including the conditions specific to your locale, such as where there are trees and buildings in your way.

Pros and Cons of Different Object Types

With those criteria in mind, let's talk about the broad categories of objects that you might consider observing. Are any a generally good, or generally bad, choice?

Object Class Advantages Disadvantages
The Moon Easy to find, moves around the sky rapidly giving a variety of time and location options. Kids love it. Observe when it is not full, and look near the edge of the shadow for the most detail. Very bright - the glare obscures dimmer objects near it. The full moon's glare can obscure the entire sky. The full moon is uninteresting in a telescope - it's "noon on the moon" and there are no shadows (although we find, at our Sidewalk Astronomy sessions, that people who have never looked through a telescope are impressed even by the full moon).
Bright Planets Saturn and Jupiter are easy to find and spectacular. Both the planets and their moons are visible. Mars and Venus can be interesting depending on time of year. Saturn & Jupiter show less detail than the photos you've seen, and require good steady air. Mars is small and shows little detail. Venus never shows detail other than its phase.
Star Clusters Clusters are available at every time of year. Some are easy to find, and look like you would expect. Globular clusters are spectacular; and all clusters are scientifically important and interesting. Not considered highly challenging, clusters are sometimes pooh-poohed by advanced amateurs. Small telescopes will show the patch of light but may not be able to resolve individual stars.
Nebulae Some are easy to find, some are easy to see. There are several kinds with very different origins, and what they tell us is scientifically interesting. Many are dim and hard to find, and they will not look like your expectations if you have seen beautiful colour photographs.
Stars Multiple stars (double, triples, etc.) can be technically interesting (a good test of optics) and some are visually interesting if they have contrasting colours or sizes. All are interesting if you imagine what it would be like to live there. Individual stars are just points of light. Some multiple stars require large telescopes to split. And some just change from one uninteresting point of light to two uninteresting points of light.
Galaxies A few galaxies are visible in small telescopes. They are so far away that they are quite impressive if you think about what you are seeing. No galaxy will show spiral arms or any structure, or any colour, in a small telescope. Those you can see at all will just be fuzzy patches of light.
Constellations It's essential that you know the constellations to find your way around the sky. But constellations are too large to look at in your telescope. They are guide posts, not destinations.

Recommendations

First, more than anything else I recommend the book

Turn Left at Orion: A Hundred Night Sky Objects to See in a Small Telescope -- and How to Find Them. Guy Consolmagno, Dan Davis, et. al., Cambridge University Press, 2004.

It is exactly what you need as a beginner: a list of objects within range of small telescopes, sketches to set reasonable expectations on what they will look like, and detailed instructions on how to find them.

To that I will add my own list of favourite objects for beginners. When a beginner asks for help, there are a dozen or so objects that are my standard targets to ensure they have something interesting and impressive to observe. Click here for my list of 20ish good beginner objects, arranged by season.



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