Beacons of night sky have colourful history

IMAGE: IAN GRIFFIN
IMAGE: IAN GRIFFIN
According to legend, centaurs were generally a fearsome and unruly bunch. 

Half human and half horse, mythology is teeming with tales of their plundering and fighting. But not all centaurs were terrible.

Chiron, whose parents were the Titan Chronus and the nymph Philyra, was a gentle, educated and inspiring teacher. Chiron was so respected by the gods that upon his death, he was raised into the sky to form the constellation we now call Centaurus.

This time of year, Centaurus rises as darkness falls. Directly above its neighbour Lupus (the Wolf), the constellation is low in the southeastern sky at 10.30 pm this week.

Centaurus straddles the milky way, which means it is a part of the sky well worth exploring either with the naked eye or, better still, binoculars. With the moon reaching first quarter phase on Monday, the next few nights will be a great time to familiarise yourself with this beautiful part of the sky.

I am sure everyone in the southern hemisphere has seen the constellation’s two brightest stars, Alpha and Beta Centauri. Sometimes called “the pointers”, thanks to their alignment with the southern cross, Alpha and Beta are the third and eleventh brightest stars in the entire sky. They delineate the knees of this celestial centaur.

Alpha is bright because it is close to us. It is the second nearest star to the sun at a distance of just over four light years. Close is, of course, a relative term. For example, if there were a road to Alpha Centauri, and you were to set off at 100kmh, it would take you roughly 45 million years to arrive at your destination.

The universe is undoubtedly a big place!

Perhaps the most stunning object in Centaurus is the giant star ball known as Omega Centauri. Located at the apex of a celestial triangle with the stars Birdun and Alnair, this fuzzy smudge of light, easily visible to the unaided eye is actually a cluster of more than a million stars which orbits our home galaxy, the Milky Way.