Orion rules winter skies
The constellation Orion the Hunter is the king of the constellations, not only in my celestial book but in the minds and imaginations of many stargazers all over the world. Even people who aren't into stargazing have seen this mighty hunter prowling across the winter skies.
Orion is one of those few constellations that actually looks like what it's supposed to be. You can clearly see the torso of Orion with broad shoulders and giant thighs. With that kind of frame some would claim that Orion should be tested for steroids!
In this week's column, I want to share some of Orion's wonderful astronomical treasures with you, and next week stay tuned for the mythological legend of the mighty hunter in the stars.
My advice sounds crazy, and your neighbors might think you've flipped out, but bundle up and go out to a dark part of your backyard or wherever you have a clear view of the southeast sky. Bring some quilts and something warm to sip. Binoculars or a small telescope are fun to have but not absolutely required.
Orion's great calling card is without a doubt the three stars in a row that make up his belt. You would think that the belt stars — Alnitak, Alnilam, and Mintaka — are part of the same close astronomical family but looks are deceiving. These stars really have nothing to do with each other. They're hundreds of light years from the Earth and each other. Call it a celestial coincidence or divine intervention that these three bright stars line up in such a perfect row from our heavenly perch in our part of the Milky Way Galaxy, home of up to a trillion stars, including our sun.
Below Orion's belt stars are three more stars in a row that aren't quite as bright. That trio makes up Orion's sword and, without much eyestrain at all, you can tell that the middle star in the sword is a fuzzy wonder. Well it truly is a wonder, but it's not a star at all. It's actually a star factory called the Great Orion Nebula.
It's about 1,600 light years away, with just one light year adding up to nearly six trillion miles. You're looking at a gigantic cloud of hydrogen gas, and even with a pair of binoculars or a small telescope, you can see some of the stars that were gravitationally born out of the hydrogen birthing gas in the last several million years. In fact the Hubble telescope has detected developing planets forming around some of these stars.
The reason we see the Orion Nebula so well is that it's literally being lit up like a neon light. The young stars within it are pouring out so much high-energy radiation that the atomic structure of the surrounding gas is disrupted, causing it to glow brightly. We're only seeing the tip of the iceberg when we see the Great Orion Nebula. There's a lot more that we can't see where hundreds and hundreds of stars are coming into celestial existence.
The other celestial hallmark of Orion is Betelgeuse on the upper left corner of the Hunter.
Like a lot of stars, Betelgeuse is an Arabic name. Arab cultures in the Middle Ages really cataloged the sky and many of their traditional star names are still in use today. What I love about the name Betelgeuse is that it translates roughly to "armpit of the great one."
You are looking at Orion's armpit, but you're probably also looking at the biggest single thing you've ever seen. Betelgeuse is considered a super red giant star and you can easily see its reddish hue with just your naked eye. The star fluctuates from roughly 400 million miles in diameter to nearly 1 billion miles in girth. Our own sun is less than 1 million miles in diameter. Betelgeuse, a star over 400 light years away, is a highly swelled star desperately using the rest of it's hydrogen supply to keep it shining, but sooner or later it will completely run out of fuel.
When that happens to stars as gargantuan as Betelgeuse, they eventually explode in a spectacular supernova. This could happen within the next million years. I wouldn't wait up for it in your lawn chair though.
There's a lot more to Orion, but the belt, the Orion Nebula, and Betelgeuse are its best features. The other thing I love about Orion are all the bright stars and constellations that surround the hunter. I call this part of the sky "Orion and His Gang" and it's my favorite part of the night sky.
I know you'll fall in love with it too.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and author of the book, "Pennsylvania Starwatch," available at bookstores and at his Web site www.lynchandthestars.com
