The Pleiades were mythologically connected with Orion, though various versions of the myth explain their relationship in different ways. A common story has Orion giving chase to the Seven Sisters, with Zeus saving them by transforming them into a flock of doves, and then into a cluster of stars. The cluster is still chased across the sky by Orion, whose own constellation lies close by to the south and east, rising and setting shortly after the Pleiades.
There is some uncertainty about the connection of the cluster and its myth, because the etymology of the name Pleiades is unclear (the interpretaion 'daughters of Pleione' appears to be a later development). It may be ultimately derived from a nautical term, suggesting that the cluster was first named by Greek navigators, with the myth of its origins appearing later. Alternatively, it may come from the Greek for 'flock of doves', with obvious connections to the story of the sisters' escape from Orion.
The Pleiades in the Sky
The Pleiades are perhaps the most easily distinguished star cluster in the entire sky, and one of the easiest to locate. Especially prominent during winter (in the northern hemisphere), the cluster falls northwestward of Orion, beyond the Hyades that form the head of Taurus the Bull. They cover an area of the sky some 110 arcminutes in diameter (nearly four times that of the disc of the Moon).
The structure of the Pleiades in the sky is a small 'dipper' shape, with Atlas forming the handle attached to a quadrangle made up of Alcyone (the brightest of the Pleiades) along with Electra, Merope and Maia. The other sisters are clustered around the western end of this 'dipper', while the star of their mother Pleione lies close to her brighter companion Atlas in the east.
The Pleiades is a young cluster in stellar terms, probably about 100 million years old, but perhaps somewhat younger or older. The young bluestars that make up the cluster are surrounded by a mesh of nebulous material that was at one time thought to represent the remnants of the original nebula from which the cluster formed. This is now thought to be unlikely, and rather the Pleiades are passing through a cloud of material unconnected with their formation as they follow their course through the Galaxy.