- The Pleiades (/ˈpliː.ədiːz, ˈpleɪ-, ˈplaɪ-/), also known as , The Seven Sisters, Messier 45, Matariki and other names by different cultures, is an asterism and an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. At a distance of about 444 light years, it is among the nearest star clusters to Earth. It is the nearest Messier object to Earth, and is the most obvious cluster to the naked eye in the night sky. It is also observed to house the reflection nebula NGC 1432, an HII region.