Sighting the Seven Sisters

One of the nice little jewels in the winter sky is the tiny Pleiades star cluster, also known as the Seven Sisters, because seven very bright stars can be seen without optical. Even from the light polluted city skies the cluster can be seen.

The little group is also known as M-45 in French astronomer Charles Messier's list of things that are not comets.

Although we can't always see seven stars, the cluster actually contains hundreds -- up to 800 depending on which astronomer you are reading--and is located some 400 light years away. A light year is the distance light travels in one year or about 6 trillion miles.

The cluster is known to many cultures around the world and is mentioned in ancient literature several times, even three times in the Bible, as well as by Homer in his Iliad and Odyssey; the next time you see a Subaru automobile look at the little name plate on the front of the car, yes, there are seven stars which stand for the Pleiades.

The cluster is in association with the constellation Taurus, the Bull and is said to ride on the bull's shoulder

To find the Pleiades start with Orion almost due south about an hour after local sunset. Shoot an imaginary line from left to right along his belt up to the right to find bright Aldebaran, the eye of the "V" shape formation of Taurus and continue along to same direction to find tiny Pleiades.

You will probably only be able to find six of the seven sisters, one of them has faded over the centuries. In binoculars the cluster is a spectacular sight but they are almost too big for a telescope field of view unless you are using a wide-angle eye-piece.

Another nearby star cluster is the open cluster Hyades which is the "V" of the face of the bull. This cluster makes a spectacular sight in binoculars and is worth the look. There is some speculation that the Pleiades and the Hyades were born at the same time from a common source.

Aldebaran is not a part of the cluster as it is only about halfway to it. The star is simply along the same line of sight as the cluster.

Since the Hyades and the Pleiades both are located along the ecliptic they are frequently visited by the moon and outer planets, in fact, just recently both Mars and Venus paid a visit and tried to look like part of the cluster.

SKYWATCH: Full moon on Friday, Feb. 14, so take your sweetheart outside at about 8 p.m. and look above the eastern horizon for the bright moon with the bright star Regulus, the brightest star in Leo, the Lion floating just to its left. Impress her with your astronomical knowledge when you tell her that Leo is a constellation of spring and that it is not far away.

On Feb. 19, the moon will pay a visit to the planet Mars and the bright star Spica. Look just above the pair after midnight on Wednesday just above the eastern horizon at about midnight. On the next night, the moon will be below and on the other side of them. The moon will continue on to pay a visit to Saturn on Friday, Feb. 21.

NEXT WEEK: Why does the moon always look the same, and more astronomical blathering.