http://astropixels.com/openclusters/images/M45-01w.jpg
Messier 45 or M45 is an open cluster in the constellation Taurus. M45 is one of the most famous night sky asterisms and is known as the Pleiades, the Seven Sisters and Subaru. The cluster is composed of extremely hot and luminous blue stars. The faint reflection nebula visible around the brightest stars is an unrelated dust cloud that the cluster is currently passing through. Gravitational interactions with other stars in the galactic neighborhood will eventualy disperse the custer about 250 million years in the future.
This open cluster has been known since antiquity and is easily visible to the naked eye. According to Kharchenko et al. (2005), the distance of M45 is 425 light years and its diameter is 15 light years. It contains 332 stars and its estimated age is 100 million years.
