Aries and the Seven Sisters. The constellation of Aries and the Pleiades (or Seven Sisters) star cluster. Aries (Latin for ram) is one of the constellations of the zodiac, located in the northern celestial hemisphere between Pisces to the west and Taurus to the east. The Pleiades (also known as the Seven Sisters and Messier 45), are an open star cluster in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky.