This column was provided by San Benito resident and amateur astronomer David Baumgartner as part of a local series on astronomy.
The Pleiades is sometimes known as one of the smallest constellations in the sky. But is it really? Well no, it’s not a constellation at all, unless you go along with the American Indians. They thought of it as a constellation by itself.
It’s actually categorized as an open star-cluster and is part of the Taurus constellation. Pleiades has other names that it may go by, such as the Seven Sisters, or I’ve heard it called the Milk Dipper. Not sure where I got the name Milk Dipper from, could have been from one of my dreams from an afternoon nap.
As you look up to the sky tonight, you can see the box shape of four stars. That would be Pleiades. The brightest is at the upper left called Alcyone. And outward from Alcyone is the Star Atlas. The star in the upper right hand corner is really two stars. So why the Seven Sisters? Since ancient times they have been referred to as seven stars. With the best eyes and under best conditions today we only see six. Did we lose one somewhere?
If you have very good eyes, you may be able to see seven stars. If you look through binoculars you can see dozens; through a telescope you may see hundreds. So the six stars most people can see are the brightest members of the cluster.
The reason why ancient people could see seven stars is that maybe one of the stars became fainter in time and that may be why today we only see six with the un-aided eye. Other people suggest that ancient ancestors often liked to count things in sevens even when there weren’t seven, mainly because it was a sacred number.
The seventh brightest star is very close to Atlas; we give it the name of Pleione. In Greek stores, the Pleiades were the seven daughters of the giant Atlas and his wife Pleione. The Greeks really had quite the imaginations. I often wondered if any of the daughters inherited their father’s size. Just a thought. Now, who has the imagination?
So next time you go outside at night look for the six or Seven Sisters. The best way to look at it is through a low powered telescope or a pair of binoculars. It really stands out quite nicely. And see if you are able to pick out that elusive seventh Sister.
Clear skies….
Up and coming events:
March 18: Full Moon
March 20: Vernal Equinox occurs
March 20: Moon passes 1.3° south of Jupiter
March 23: Moon is at perigee (229,758 miles from Earth)
March 25: Last Quarter Moon
March 27: Moon passes 4° south of Mars
March 28: Moon passes 7° south of Venus
March 28: Moon passes 4° south of Saturn
March 29: Venus passes 2° north of Saturn
March 30: Moon passes 4° south of Jupiter
March 30: Moon passes 4° south of Neptune