Jimmy Westlake: A tale of two star clusters
November 25, 2013
Steamboat Springs — On cold, crisp November evenings, you can spot two glittering star clusters in the constellation of Taurus the Bull, high up in the eastern sky around 8 p.m. They are the Hyades and the Pleiades star clusters.
The Hyades cluster is the closest star cluster to Earth and forms the familiar V-shaped face of Taurus, with the bright orange giant star Aldebaran marking one of his glaring eyes. Aldebaran itself is not a member of the Hyades but appears superimposed in front of the cluster as a foreground star, only half as far away. The Hyades cluster is about 150 light years from Earth.
Preceding the stars of the Hyades as they move westward across the sky is Taurus' second star cluster, the Pleiades, marking the bull's shoulder. Also known as the Seven Sisters, the Pleiades star cluster is more than twice as far from us as the Hyades cluster, and so it appears much smaller in size. The Pleiades cluster is about 400 light years from Earth.
Both the Hyades and Pleiades star clusters are steeped in ancient legend and have been pondered by curious eyes since antiquity. Here's just a sample of the star lore surrounding these two clusters:
Hyas was the son of a Titan named Atlas. His seven half-sisters by a different mother were the Hyades, a name that means "the rainy ones." Hyas grew into a renowned archer and hunter, but one day wound up being killed by his prey — a wild boar. His sisters were so overcome with grief that they wept themselves to death. Zeus, the king of the Greek gods, immortalized the sisters by placing them among the stars as our Hyades star cluster. During the rainy months of April and May, the Hyades cannot be seen because they are too close to the sun in our daytime sky. The Greeks considered the springtime rains as the never-ending tears of the Hyades, grieving for their fallen brother.
The Pleiades were the seven half-sisters of the Hyades by yet another mother. After Zeus and the Olympians defeated Atlas and the other Titans in the great war for control of the universe, Atlas' punishment was to toil for eternity, holding up the dome of the sky. Unable to protect his daughters from harm, Atlas had to watch helplessly as the big brute Orion chased after the seven beautiful Pleiades. Zeus took pity on them, and first changed them into doves so that they might escape Orion's advances before finally changing them into the seven twinkling stars of our Pleiades star cluster, just out of Orion's reach in the sky. He also placed them in the heavens beside their grieving half-sisters, the Hyades.
Recommended Stories For You
Look for the Hyades and Pleiades star clusters high up in the eastern sky around 8 p.m. in late November and early December. Binoculars will enhance your view.
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. His “Celestial News” column appears weekly in the Steamboat Today newspaper and his “Cosmic Moment” radio spots can be heard on local radio station KFMU. Check out "Jimmy's 2014 Cosmic Calendar" of sky events on his website at http://www.jwestlake.com. It features 12 of his best astrophotographs and a day-by day listing of cool celestial events that you and your family can enjoy watching in 2014. Proceeds from the sale of Cosmic Calendars help to support the CMC SKY Club.