Beginner’s guide to the winter sky


One of the great ironies of the holiday season is that a whole lot of telescopes end up under trees but few of them get used until May. It’s hard to point a ‘scope when your feet are frozen to the ground. Waiting is a mistake. The best of all constellations is visible in winter, and this year, you have the opportunity of seeing the best of the planets.

Most folks start with the moon, of course. Luna is relatively easy to find, and you can’t beat the view of those craters in a small telescope or even binoculars.

A common error is to try the view from indoors through a window. Do yourself a favor and take your telescope outside. The view through glass will be distorted and ultimately disappointing. It’s not the way to start your observing career.

Next, you’ll want to take a look at Venus and Mars. Look toward the southwest in deep evening twilight. Venus is hard to miss as the brightest object in the night sky besides the moon. Mars is that orange star-like object up and to the left of Venus.

Venus has phases just like the moon’s. Right now, your telescope will reveal a fat waning crescent that will shrink to a smaller one in the coming weeks as Venus approaches Earth. Continue to observe Venus every chance you get. As it gets closer to us, it will increase in app aren’t size as its crescent shrinks. At some point, you should be able to see its crescent shape in simple binoculars.

Mars will look like a reddish dot. Sorry. With Mars, that’s pretty much all you get.

You early risers should check out Jupiter in the morning. Right before morning twilight, look for the brightest “star” in the southeast. Your telescope should reveal three or four its four brightest moons lined up around the planet. At higher magnification, you should be able to spot Jupiter’s cloud bands running like parallel zebra stripes around the planet.

Beyond that, you’ll have to learn the sky and its constellations, which is no easy task. Luckily, Orion is well placed in the evening sky in winter. The Hunter, as he is sometimes called, is good starter constellation for all you newbies out there in telescope land. Even the smallest of department store telescopes will show a few objects in Orion.

One way to maximize your observing pleasure in winter is to carefully plan your stargazing session. One technique is the time-honored method of “constellation hopping.” Take a familiar star grouping and work your way through it.

Lets find it first. Look south around 10 P.M. You’ll see a line of three bright stars, which form the belt of the Hunter. The bright stars above the belt represent Orion’s shoulders. The reddish star on the left is the old supergiant called Betelgeuse.

To the right is Bellatrix. Orion’s feet are called Saiph, to the left, and Rigel, to the right.

The first object to look for in a telescope is the multiple star system called Sigma Orionis. Find Alnitak, the left-most belt star. Sigma, the naked-eye star just below it, should split into three stars at high magnification. The main star, called Sigma AB. AB is really two very bright and massive stars orbiting each other so closely that you cannot split them in a telescope. Nearby Sigma D has a distinctly reddish glow. Sigma E is a bit farther from D than D is from AB. You are looking at a system of five stars, two of which you cannot see, that are all orbiting each other in a complex cosmic dance.

Two of the stars in the belt are also multiple star systems. Look for single, dim companions next to Alnitak and Mintaka, the right-most star in the belt. Whether you can see them or not depends on the clarity of the sky and the size of your telescope.

Below Alnitak and Sigma is a great binocular object, the vertical line of stars called the Sword of Orion. Near the bottom end of the Sword is the best telescope target in the heavens, the Great Nebula. Look for a complex fuzzy cloud, a glorious mass of glowing hydrogen in which stars are being born. At high magnification, the four stars in a rough square at the center of the nebula are called the Trapezium. These stars are newly born out of the hydrogen gas that surrounds them.

Single stars are much too far away to look like anything more than a point of light in a telescope. However, a quick look at Betelgeuse, Orion’s left shoulder, will help to bring out its reddish hue. You are looking at a star as large as the diameter of Earth’s orbit around the sun — 200 million miles wide. It has lived its short, 100-million-year life burning hydrogen at a prodigious rate. It has now swelled to enormous size in preparation for its death in a mere million years or so.

If you have difficulty finding these objects, perhaps the person who gave you the telescope forgot to give you a good set of beginner’s star maps. I’d recommend Guy Consolmagno’s Turn left at Orion. With it and a telescope of practically any size, you’ll find plenty to see.

So bundle up and go outside. The universe awaits.

Tom Burns


Tom Burns is director of the Perkins Observatory in Delaware.

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