His ‘Gang’ is out in full force

As it does every year, the great constellation Orion the Hunter starts showing up late in the evenings in the low eastern sky about mid-to-late November and I always look forward to his arrival. He’s like an old buddy of mine, although I know he has lots of other pals that look forward to seeing him rise from his summer slumber.

Without a doubt, Orion is certainly the anchor constellation in the winter skies and arguably the best and brightest constellation in the sky. Even in heavily lit urban skies, Orion’s stars pierce through.

To some people, the constellation resembles a crooked bow tie, but others see an hourglass. It’s supposed to outline the torso of a giant hermit hunter, at least according to Greek mythology. This bulked up hunter is said to be holding a lion by the tail, although some imaginations see him holding up a shield or a bow.

It’s quite a tale as to how Orion became part of the night sky, and I’ll tell you all about it in next week’s Starwatch along with other stories of the great constellation.

This week, I want to cover at least some of Orion’s great astronomical treasures — although to cover them all I would pretty much take over this entire section of the paper!

Orion is more or less the centerpiece constellation of what some call the “Tower of Brilliance” or the “Winter Circle,” but what I like to call “Orion and his Gang.” Since November it has migrated westward from night to night, rising earlier and earlier.

Now, at the start of evening Orion is already standing proudly well above the southeastern horizon. By 9 p.m. you can see the entire splendor of Orion and his Gang with fellow constellations like Taurus the Bull, Auriga the Charioteer, Gemini the Twins, Canis Major the Big Dog and Canis Minor the Little Dog, all of which contain brilliantly bright stars. In fact, out of the 20 brightest stars seen from our Butler skies through the course of the year, 11 of them are concentrated in Orion’s gang.

Orion’s greatest visual assets are the three nearly identical bright stars that make up his belt. They are Alnitak, Alnilam and Mintaka. Nowhere else in the sky, no matter where you look from Earth, will you see three stars as bright as they are lined up so nicely.

It’s easy to see how you would be tempted to conclude that those three stars are physically related to each other in some kind of stellar system. However, they have nothing to do with each other, and even though they appear close together, they’re actually hundreds of light-years apart.

Even though we see constellations as two dimensional “pictures” in the celestial dome, we’re actually looking into a three dimensional space. Alnitak is 800 light-years away, Alnilam is 1,300 light-years distant and Mintaka shines at us from 900 light-years. It’s just by sheer coincidence (or not?) that these stars line up as they do from our vantage on Earth.

There’s another coincidental line up of three dimmer stars to the lower right of Orion’s belt that depict his sword, but even with your naked eyes, glasses included, you can see the middle star in the sword is a little fuzzy. No, it’s not your eyes. What you’re seeing is a fantastically large cosmic cloud of hydrogen called a nebula where new stars are being formed.

The great Orion Nebula, as it’s known, is more than 1,400 light-years away and more than 30 light-years across. To get an idea of how big that is, you could line up 20,000 of our solar systems end to end across it!

This colossal birthing ground of stars would be invisible if it weren’t for four very energetic stars that were born out of it and light up the nebula like a florescent light. This makes the Orion Nebula an emission nebula.

Even with a small telescope you should be able to resolve the four stars arranged in the shape of a tiny baseball diamond. Formally, it’s known as the Trapezium, and all four of its members are probably less than a million years old, which in the life of stars makes them infants.

On the upper left hand corner of Orion is without a doubt the biggest single thing you’ve ever seen. It’s the star Betelgeuse, which is an Arabic name that debatably translates into “armpit of the great one.” That’s right, Betelgeuse marks the armpit of the great hunter.

Astronomers categorize it as a super red giant more than 1,000 times larger than our sun, which would give it a diameter of nearly a billion miles! If you were to put it in the place of our sun, its girth would stretch out to the orbit of Jupiter. Mercury, Venus, Earth and Mars would all be engulfed by the behemoth.

Betelgeuse is considerably younger than our sun, thought to be less than ten million years old. Our sun has been around for about five billion years and may make it another five billion.

Supergiant stars like Betelgeuse are not long for this galaxy and universe because they very rapidly deplete their resources. They’re the gas guzzlers of the stellar world. In fact, within a million years or possibly even a few thousand years, Betelgeuse will meet its demise and it won’t go out quietly. Stars the size of Betelgeuse literally blow themselves to bits in a supernova explosion. When that happens, the explosion could be nearly as bright as a full moon and stay that bright for at least a couple of weeks.

That will make for quite a show, but I wouldn’t wait up for it. You could lose an astronomical amount of sleep for nothing!

There are many more celestial treasures in Orion. Just put the name Orion in any search engine and read away, or better yet, download a planetarium program. My favorite is “Stellarium.” Not only is it great, but it’s also free.

Whatever you do, with or without a telescope, try to view Orion from the truly dark skies in the countryside. You’ll thank me for sending you out there!

Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, “Pennsylvania Starwatch,” available at bookstores and at www.lynchandthestars.com.