Jimmy Westlake: Orion and Company
January 17, 2012
Winter is an excellent time to start learning the constellations. The winter sky contains more bright stars and constellations than any other season of the year. Chances are you're already familiar with one or two of our winter star patterns, but you might not know them by name.
The heart of the winter sky is arguably the most magnificent constellation in all the heavens, the great hunter Orion. Three bright stars in a row mark Orion's belt, and above, the stars Betelgeuse and Bellatrix twinkle at his shoulders. Below, the stars Saiph and Rigel represent his feet, giving Orion the overall shape of an hourglass. The familiar triplet of stars in Orion's belt plus the three fainter ones nearby that mark his sword are often mistaken by tyros for the Big Dipper. In fact, I grew up thinking that the stars of Orion formed the Big Dipper. No one ever told me differently. But just the same, on every cold winter night of the year, the epic drama staring Orion plays out on the celestial stage.
The mighty hunter, with shield and club raised, is locked in fierce combat with Taurus the Bull, pushing him across the sky toward the west. The distinctive face of Taurus is marked by the V-shaped Hyades star cluster and punctuated with the bright star Aldebaran, representing his glaring red eye. The little-dipper-shaped Pleiades star cluster lies on the Bull's shoulder.
Barking at Orion's heels is his faithful hunting dog, Canis Major, whose nose is marked by the brightest star in the night, Sirius, also known by its nickname, the Dog Star. Nearby, the little pup Canis Minor is yapping up a storm at the sight of the big bullfight.
Orion's favorite animal to hunt was the rabbit, not the bull, and all the commotion has flushed Lepus the rabbit from the grass at Orion's feet. Off he goes, scurrying into the night.
American poet Robert Frost evoked Orion the Hunter in his poem "The Star Splitter":
"You know, Orion always comes up sideways, throwing a leg up over our fence of mountains and, rising on his hands, he looks in on me, busy by lantern light with something I should have done by daylight and, indeed, after the ground has frozen, I should have done before it froze. And a gust hurls a handful of waste leaves at my smoky lantern chimney to make fun of my way of doing things, or else fun at Orion's having caught me. Has a man, I should like to ask, no rights these forces are obliged to pay respects to?"
In another poem, Frost immortalizes Orion's hunting companion, Canis Major:
"Canis Major, that heavenly beast with a star in one eye, gives a leap in the east. He dances upright all the way to the west and never once drops on his forefeet to rest. I'm a poor underdog, but tonight I will bark with the Great Overdog that romps through the dark!"
Look for Orion and Company in the southeastern sky around 8 p.m. and high in the south by 11 p.m. in mid-January.
Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. Check out Jimmy's website at http://www.jwestlake.com.