The main player
Orion the Hunter is such a great constellation and I have to believe many stargazers share the same opinion. Even if you’re not all that much of a stargazer you can’t help but notice the mighty celestial hunter prowling westward across the Butler winter heavens. It’s one of the few constellations that actually resembles what it’s supposed to be. With just a passing glance you can easily see the torso of Orion with his broad shoulders and gigantic thighs. To me and others, Orion also resembles a giant hourglass oriented diagonally in the evening southeastern sky. In this week’s Skywatch I want to feature at least a few of Orion’s many astronomical treasures. Next week will be story time as I’ll share some of the great mythological tales involving Orion.
Armed with many layers of clothes, boots and your warmest hat, you can brave the January cold. Something warm to sip on really helps as well! If you can be out in the countryside, great, but even in suburban skies plagued with moderate light pollution, I think you’ll like what you see. Binoculars and/or a small telescope enhance the experience but are not strictly necessary.
Orion’s great calling card is, without a doubt, his belt, made up of three bright stars close together in a nearly straight line. Even though the belt stars Alnitak, Alnilam and Mintaka look close together, they are physically nowhere near each other. They’re not only hundreds of light-years from Earth, but hundreds of light-years from each other. Call it a celestial coincidence or divine intervention that these stars align as orderly as they do from our vantage point in the Milky Way galaxy.
Below Orion’s belt stars, there are three more stars in a short line that aren’t quite as bright. That trio makes up Orion’s sword sheath, and without too much eyestrain, you can see that the middle star is “fuzzy.” That’s not a single star but rather a stellar nursery. You’re witnessing the Great Orion Nebula. It’s around 1,500 light-years away, with just one light year equaling nearly six trillion miles! It’s a gigantic cloud of hydrogen gas, and with a small telescope, or even a decent pair of binoculars, you can see a tiny cluster of at least four stars near the center. These infant stars were born gravitationally out of this giant mass of hydrogen gas during the last several million years, although one of the stars may be as young as 50,000 years old, which is extremely young when you’re talking stellar. The Hubble telescope has even detected what may be planets are developing around the new stars.
As intriguing as the Orion Nebula is through a “conventional” visual telescope, it’s incredible through a smart photographic telescope like a ZWO See Star S50, or S30, both less than $600. I really think these scopes are the wave of the future. They’re easy to operate and are nearly light pollution-proof. Anyway, with one of these photographic scopes you’ll see more structure to the nebula and it’ll be in color, mainly a mauvish tint. Attached is a photo of the Orion Nebula I took with my SeeStar S50.
The reason we see the Orion Nebula as well as we do is that it’s literally being lit up like a fluorescent light. The very young and extremely active stars hidden within the nebula are emitting so much intense radiation that the atomic structure of the surrounding gas is disrupted, causing it to glow as brightly as it does. We’re only seeing just a small part of the Orion Nebula though. There’s a lot more to it that isn’t glowing, but thousands and thousands of stars are still forming within it that will eventually light up the surrounding hydrogen womb.
Another one of Orion’s celestial hallmarks is the bright star Betelgeuse in the upper left corner of the hunter. Like many stars, Betelgeuse has an Arabic name. Arabic cultures in the Middle Ages and earlier cataloged the night sky, and many of their star names are still in use today. What I love about the name Betelgeuse is that it roughly translates to English as “armpit of the great one.” As you can see in the diagram Betelgeuse actually marks the armpit of Orion.
Astronomically, Betelgeuse is one of the single biggest things you’ve ever seen. It’s considered a red supergiant star, and even with the naked eye you can detect its reddish hue. Betelgeuse fluctuates in diameter and brightness. Most astronomers believe its diameter fluctuates from about 400 million miles to over 800 million miles. Our own home star, the sun isn’t even a million miles in diameter. Betelgeuse is about 600 light-years from Earth, and is dying a slow death that someday will turn extremely violent! It’s using up all of the hydrogen and helium fuel in its core. When that happens to extremely massive stars like Betelgeuse they become extremely unstable, and eventually the star explodes in a spectacular fashion. This is called a supernova explosion. Many astronomers think this could happen to Betelgeuse within a million years, maybe even next week. I wouldn’t wait up for it outside in your lawn chair, though. You could turn into a Popsicle!
There are many more astronomical treasures in the constellation Orion that you can explore with apps like Sky Guide and many others, but its belt, the Orion Nebula and Betelgeuse are the big three. What I also love about Orion are all the other bright stars and constellations that surround the great heavenly hunter. I like to call this part of the sky “Orion and his gang,” and this winter, the very bright planet Jupiter is a member of the gang. Jupiter’s also the brightest starlike object in the entire night sky!
Get to know the main player of the winter sky, and I know you’ll fall in love with him too. Next week — the great stories of Orion!
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is also the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and at adventurepublications.net. Contact him at mikewlynch@comcast.net.
