Celestial News: Centaurus Peeks In

Centaurus is a magnificent constellation of springtime, seen here in its entirety from the Big Island of Hawaii.  From Colorado, we can only see the top half of the Centaur.  Alpha Centauri is the closest star system to our own, just 4.3 light years away, but it does not clear Colorado's horizon. Magnificent star cluster Omega Centauri (inset) contains millions of stars, lies 16,000 light years from Earth, and can be glimpsed from Colorado.  Photos by Jimmy Westlake, 2010.

By Jimmy Westlake, professor of physical science, Alpine Campus

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 BC.  It is thought to represent the centaur named Chiron.  While 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, like Hercules, Theseus, and Jason.  During one of Hercules’ many rowdy scuffles, Chiron was accidentally 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 was mercifully allowed to die.  Zeus then immortalized the image of Chiron among the stars as our constellation of Centaurus.

Twenty-five hundred 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 can only 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 around 11:00 PM in early May (10:00 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, since 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.

Professor 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 around the world. His “Celestial News” column appears weekly in the Steamboat Pilot newspaper. His “Cosmic Moment” radio spots can be heard on local radio station KFMU.  Also, check out Jimmy’s website at www.jwestlake.com.