Beginner’s guide to observing with holiday telescope


By Tom Burns - Stargazing



You’ll never feel more like Santa than when you buy a child a telescope for Christmas. You’ll never feel more like the Grinch when you step outside on Christmas night with little Justine or Jimmy and hear the plaintive cry, “Find something for me, beloved parental unit.”

Well, parental units, the sky is full of astro-goodies you can see in a small telescope. (Admit it. You know you really bought the telescope for yourself. Jimmy and Justine can come along for the ride.)

Of course, there’s always the moon — craters, no extra charge. However, the moon won’t be easily visible in the early evening sky until Jan. 6.

With one exception, the bright planets have set by the time darkness comes, or they are too low to see.

However, Jupiter is that bright point of light low in the southwest just after dark. Look for it at your new telescope’s lowest power or in binoculars, and you’ll see some or all of its four brightest Galilean moons. Look for its dark cloud bands stretched like zebra stripes around the planet at higher power.

Granted, Jupiter and the moon are mind-blowing experiences. By the time your children (and you) have seen them for the 28th time, you’ll be wondering why you didn’t get your children Grand Theft Auto V instead.

Don’t fret. There’s plenty more to see. The very best astronomical objects for small telescopes are visible in the winter.

The next step is to go beyond the solar system to the “deep sky.”

But first, you’ll need a good set of star charts. Those star-chart apps for your phone are a good place to start. They will help you find a bright planet or three, but they won’t do the job on the fainter objects located outside the solar system, the so-called “deep-sky objects.”

If your telescope is equipped with computer control, you can always find the objects you want to observe. However, you’ll have to learn to use the control system first, which takes more time than your kids will tolerate.

Besides, in my opinion, there’s no greater joy than learning how to find astronomical objects on your own.

So do yourself a favor, purchase a good set of printed star charts. In my opinion, the best collection for beginners is “Turn Left at Orion: Hundreds of Night Sky Objects to See in a Home Telescope – and How to Find Them” by Guy Consolmagno.

Also, buy the telescope before Christmas, take it outside, and learn to find a few objects or learn to use the computer-control system.

After Christmas, your children will think you’re an astronerd of the highest order, and you won’t spend most of January wondering why you blew all that money on the cursed thing.

The best of all deep-sky objects in binos or a small telescope is probably the Pleiades, or Seven Sisters, a beautiful cluster of stars visible right above the V-shaped head of Taurus the Bull.

Taurus’s head and the Pleiades are visible to the unaided eye, making them a snap to find. Start by looking high in the east just after dark for the “V,” tilted on its side.

The Hyades, the traditional name for Taurus’s head, is a spectacular binocular object in its own right.

The Pleiades are above the Hyades. Look for a tiny dipper-shaped collection of six stars.

Point your ‘scope at the dipper using your lowest power eyepiece. Even better, check it out in binoculars first. The cluster will explode into a dozen or more stars.

The stars you are seeing are very young and blue. None of the bright stars of the Pleiades have had time to evolve into red giants, implying that the cluster is very young, perhaps 50 million years old.

The cluster is so bright and spread out because it’s relatively close to us at 440 or so light-years away. (“Relatively” is, of course, a relative term. One light-year is equal to six trillion miles. As we shall see, most star clusters are much farther away.)

The stars of the Pleiades were all born out of the same hydrogen cloud, and they haven’t had time to drift apart.

The 800 stars of the Pleiades are still crowded together in a tiny region of space 35 light-years wide. If that number sounds big, consider that the average distance from one star to another in our sector of the Milky Way is about seven light-years.

The next stop on your telescopic tour should be one of those gassy, star-birthing regions.

Below the head of Taurus, you will see the bright constellation Orion the Hunter. He is defined by the three bright stars in a straight line that form his belt. Below the belt hangs a string of stars that form Orion’s sword. Near the bottom end of the sword, you will find an irregular patch of light with a few stars near its center.

The milky patch is the Great Nebula, a cloud of glowing hydrogen gas 120 trillion miles wide. The stars you see are only about a million years old — stellar babies.

Even at 1,500 light-years away, the nebula is visible to the unaided eye from a dark, rural sky. You should be able to see it in binoculars from inside a suburban area now that you know where to look.

But wait. There’s more. Hundreds of astronomical jewels are within the range of a small telescope. Your journey has just begun.

After you’ve seen the targets mentioned above, an excellent place to go next is the collection of star clusters in the constellation Cassiopeia.

They are prime targets because they look good in even small telescopes and are relatively easy to find.

First, some background. Star clusters are collections of stars of about the same age. Like the Pleiades, the stars are close together because they were born out of the same cloud of hydrogen gas.

Their mutual gravitational attraction only loosely connects the stars of a cluster. As a result, they are slowly drifting apart.

Eventually, they will travel away from each other and take their lonely places in the Milky Way. In the meantime, those primarily young stars are visible in the same low-power telescope field.

A few million years will pass before they aren’t clustered anymore. Check them out before it’s too late.

The area’s showpiece is probably the Double Cluster, which, technically speaking, is just across the Cassiopeian border in Perseus. It consists of two star clusters that fit nicely in the same medium-power telescope field.

The Double Cluster is a whopping 7,500 light-years away. Despite its great distance, it looks like two piles of glowing gems stacked up next to each other.

Next, look for NGC 663. You’ll see over a dozen bright, pale-yellow stars surrounded by a haze of light. The haze consists of the unresolved glow of many other stars that your’ scope is too small to see.

My personal favorite is NGC 7789, but I own a telescope about the size of a Chevy Spark. In a larger ’scope, you’ll see at least 100 stars surrounded by the same fuzzy glow as NGC 663. In a smaller ’scope, the cluster looks like a ball of light with no individual stars visible.

NGC 7789 is huge, over 40 light-years wide, and far away at 7,600 light-years. No wonder this ball of 1,000 or so stars doesn’t resolve into individual stars very well.

At “only” 4,600 light-years away, M 52 is one of the prettiest clusters in the constellation. You’ll see a few bright stars, but even in a small ‘scope, the background haze looks lumpy and rich, as if dozens of stars are just on the verge of popping out.

NGC 457 is 9,000 light-years distant, so don’t expect much from it. You’ll see a hazy, elongated glow with only a few bright stars visible. However, one of those stars deserves special attention.

The brightest of NGC 457’s stars, called Phi, generates considerable controversy among astronomers. Because Phi is so much brighter than the other stars, you might assume that it is not a part of the cluster and is much closer than the rest of the stars.

However, Phi appears to be moving through space at the same velocity as the rest of the cluster. If it lies at the same distance as the cluster, it must be producing prodigious energy to be so bright.

As it turns out, Phi is a multiple-star system with at least five component stars traveling together through space. Its main component is 170,000 times more luminous than the sun, making it one of the most energetic stars known.

Stars like Phi are called yellow supergiants. They are dying stars going through a burst of energy before they finally kick the comic bucket.

You’ll find a lot more clusters. Explore, enjoy, and put that new telescope through its paces.

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By Tom Burns

Stargazing

Tom Burns is the former director of the Perkins Observatory in Delaware.

Tom Burns is the former director of the Perkins Observatory in Delaware.