Jimmy Westlake: Centaurus peeks in
May 4, 2010
Steamboat Springs — Centaurs figured heavily in the mythology of the ancient Greeks, so much so that two of them are immortalized in the stars as our constellations of Sagittarius the Archer and Centaurus the Centaur. The legend of these half-man, half-horse beasts might have originated when someone long ago first saw humans on horseback and imagined them to be some sort of human-equine hybrid.
Centaurus is one of our most ancient constellations, first mentioned in Greek literature from the fourth century B.C. It is thought to represent the centaur named Chiron. Although most of the centaurs were considered to be barbaric, uncouth beasts, Chiron was an exception. He was a wise old centaur that served as the personal tutor of many Greek heroes such as Hercules, Theseus and Jason.
During one of Hercules' many rowdy scuffles, Chiron accidentally was nicked by one of Hercules' poisoned arrows. Being immortal, Chiron could not die, but the agony of the wound was so severe that he begged Zeus to revoke his immortality. This he did, and Chiron mercifully was allowed to die. Zeus then immortalized the image of Chiron among the stars as our constellation of Centaurus.
About 2,500 years ago, the constellation of Centaurus could be seen in its entirety from mid-northern latitudes, but the perpetual wobbling of the Earth on its axis has since carried the stars of the Centaur so far south that we only can see his human half from Colorado. Every spring, he briefly pops his head up above our southern mountains and peeks in on us.
You can see Centaurus, too, peeking in on us. Go outside at about 11 p.m. early this month (10 p.m. in late May) and look due south, underneath the bright blue star Spica. There you'll spot the Centaur's triangular head, his arms and human torso, but his equine body remains hidden from view. To see Centaurus in his entirety, one would need to travel south to the latitude of the tropics.
One of the many celestial treasures found within the boundaries of Centaurus is the largest and most beautiful of the globular star clusters, Omega Centauri. As large as the full moon and containing millions of stars, Omega Centauri is visible to the unaided eye as a fuzzy star and, when viewed through a telescope, is nothing short of breathtaking. To see this cosmic wonder from Colorado, one must have a clear view all the way down to the southern horizon because it only manages to rise a few degrees into our sky. Try climbing a hill or mountain with a clear view to the south and aim your binoculars at Omega. You won't be disappointed.
Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. He is an avid astronomer whose photographs and articles have been published all across the world. Check out Jimmy's astrophotography website at http://www.jwestlake.com.