M45 - PLEIADES

The Pleiades (M45), also known as the Seven Sisters, is the most famous and recognizable star cluster in the sky, located approximately 444 light-years from Earth in the constellation Taurus. It is a young open cluster containing over 1,000 confirmed member stars, though the brightest six to seven are easily visible to the naked eye, forming a distinctive small dipper-like pattern that has been recognized by virtually every human culture throughout history. The cluster shines at a combined magnitude of 1.6, making it the brightest star cluster in the sky. The Pleiades is estimated to be about 100 million years old, and its most prominent members are hot, blue-white B-type stars named after figures from Greek mythology: Alcyone, Atlas, Electra, Maia, Merope, Taygeta, and Pleione. Long-exposure photographs reveal that the cluster is currently passing through an unrelated interstellar dust cloud, which produces the stunning blue reflection nebulosity that surrounds the brightest stars, particularly prominent around Merope. This nebulosity was once thought to be remnant material from the cluster's formation, but proper motion studies have confirmed it is an unrelated dust cloud. The Pleiades has featured prominently in the mythology, calendars, and navigation systems of cultures worldwide, from the Aboriginal Australians to the Maya, Japanese, and Maori peoples. Messier cataloged it in 1769, though its inclusion in the catalog is somewhat surprising given that it is obviously not a comet. The Pleiades is best enjoyed with the naked eye or binoculars. Binoculars reveal several dozen stars in a gorgeous field, while telescopes are actually less effective because the cluster is so large, spanning about 2 degrees of sky.

Contains over 1,000 stars spanning about 17 light-years at a distance of 444 light-years, with the brightest members being luminous B-type stars about 100 million years old.