The Pleiades is an open star cluster located in the constellation of Taurus, the Bull. It is about 440 light years from our solar system. This open cluster, also known as the Pleiades and the Seven Sisters, contains at least 500 stars. The blue nebula that appears to surround this star cluster is a reflection nebula. Light from the stars in the cluster shines through and reflects off a cold cloud of gas and dust in space.
The cluster is an easy object to see even without a telescope. In 1769 Charles Messier made it the forty fifth object, M45, of his famous catalog.
This image is a composite from images taken with the Palomar Observatory's 48-inch Samuel Oschin Telescope as a part of the Second Palomar Observatory Sky Survey.