The Pleiades open star cluster (M45), often known as the Seven Sisters, as seen with binoculars. Located 410 light years away in the constellation of Taurus, M45 consists of some 400 stars in a spherical volume of space 25 light years in radius. They range from hot young blue stars to older red ones. The seven brightest, which can be seen with the naked eye, are all young stars no more than 50 million years old; they are Alcyone (magnitude 2.9), Atlas (3.6) Electra (3.7), Maia (3.9), Merope (4.2), Taygete (4.3) & Pleione (5.1 but variable).