An open cluster of stars in the constellation Taurus, clearly visible to the naked eye. It is estimated to contain between 300 and 500 members within a sphere 30 light years across, and is 400 light years away. The stars are embedded in a reflection nebula of cold gas and dust that appears blue in colour photographs. The cluster is young by astronomical standards, about 50 million years old, and contains some very massive bright stars.
The popular name for the Pleiades is the Seven Sisters, but most people are able to distinguish only six stars with the naked eye.
