Jimmy Westlake's Celestial News column appears monthly in the Steamboat Today.
Find more columns by Westlake here.
Steamboat Springs High overhead as darkness falls on cold January evenings is a tiny cluster of stars that is often mistaken for the Little Dipper.
Although it does have a dipper shape, with a tiny little bowl and a tiny little handle, its real name is the Pleiades star cluster. It is the 45th object in Charles Messier’s famous catalog of comet look-alikes (M45), and is popularly known as the Seven Sisters. In Japan, it is called the Subaru. A likeness of the Pleiades star cluster adorns every Subaru car out there on the road.
A person with average vision should have no difficulty in seeing the six brightest stars in the Pleiades and a bit of careful searching should reveal a seventh faint star, as well. A person with exceptional eyesight might make out as many as eight, nine or even 10 stars with their unaided eye. How many can you see?
The name Seven Sisters refers to the seven daughters of Atlas and Pleione from Greek mythology. Only five of the seven brightest stars are named for sisters; the other two represent their parents. In order of decreasing brightness, the seven brightest stars are named Alcyone, Atlas, Electra, Maia, Merope, Taygeta and Pleione. Two stars at the edge of visibility represent the other two sisters, Celaeno and Sterope. A simple pair of binoculars clearly will reveal the entire family and dozens more stars to boot.
Greek mythology explains that the big brute Orion the Hunter, also seen in our winter stars, was pursuing the beautiful daughters of Atlas and Pleione. Zeus, the king of the Greek gods, heard their cries for help and transformed the maidens into white doves so that they could escape Orion’s lustful pursuit. They flew high into the heavens and still are seen today as our Pleiades star cluster. The three stars of Orion’s Belt point upward like an arrow toward the Seven Sisters.
A more modern, scientific explanation for the lovely Seven Sisters star cluster is that they were, indeed, all born as siblings from the same cloud of interstellar gas about 100-million years ago. There are more than 1,000 member stars in the Pleiades cluster, all placed about 410 light-years away from our solar system. That means, when you look at the Pleiades, you are looking back in time and seeing them as they were 410 years ago.
The Pleiades cluster stood alone as a separate constellation for many centuries. Thousands of years ago, the author of the biblical book of Job asked, “Canst thou bind the sweet influences of Pleiades or loose the bands of Orion?” Modern astronomers have included it within the boundaries of our large constellation of Taurus the Bull. The tiny cluster now lies on the bull’s shoulder.
On the evening of Feb. 1, the waxing gibbous moon will appear very close to the Pleiades star cluster. Although the bright moonlight likely will drown out the fainter members of the Pleiades, you still should be able to spot the twinkly star cluster just above the moon.
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 his website at www.jwestlake.com.