The Pleiades, or Seven Sisters (Messier
object 45 or M45), is an open star cluster containing middle-aged hot B-type stars located in the constellation
. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky. Pleiades has several meanings in different cultures and traditions.
Known as the finest open star-cluster in the Heavens. Six or seven of the brighter stars are distinguishable with the unaided eye, and more have been seen by persons of acute vision. Position of central star (Alcyone) 3h. 421m. + 23° 52'. m45_180sx15_D70_EP180_9_19_07.jpg image credit to http://www.surmont.com
The cluster is dominated by hot blue and extremely luminous stars that have formed within the last 100 million years. Dust that forms a faint reflection nebulosity around the brightest stars was thought at first to be left over from the formation of the cluster (hence the alternate name Maia Nebula after the star Maia), but is now known to be an unrelated dust cloud in the interstellar medium that the stars are currently passing through. Astronomers estimate that the cluster will survive for about another 250 million years, after which it will disperse due to gravitational interactions with its galactic neighborhood.
[hide][top]How to Find the Pleaides
In most darker skies, M45 is a naked eye object which can be found easily if one follows the line of Orion
's Belt prolonged in the direction opposite to that of Sirius
(the brightest star visible) will lead to the bright and beautiful star of the 1st magnitude known as Aldebaran. Once Aldebaran is found, a little further in a north-westerly direction, one will find the celebrated group of "The Pleiades
," or Seven Sisters of classic renown.
The principal Pleiades star is Alcyone.
[hide][top]Pleiades the Seven Sisters - Star Lore & Myth
The Pleiades (M45) were seven sisters, daughters of Atlas and the nymph Pleione. One day, when strolling through the forest, the huntsman Orion
came upon them and was so attracted by their beauty that he pursued them. They fled ; Orion was about to overtake them when Jupiter
changed them to doves and took them to heaven. The fact that there are but six visible has two explanations. One is that one of them, Merone, married a mortal and her light was put out for the act.
Another is that one of them, Electra, was so grieved at the fall of Troy that never could she bear again to be seen by human eyes. In the midst of the group there is one sister brighter than the rest. Her name is Alcyone. The telescope
reveals 200 stars in this cluster.
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