Open clusters are small groups of stars, which are bonded together by the gravitational forces. They contain significantly fewer members and are younger compared to globular clusters. Open clusters were probably formed from giant clouds of interstellar gas and dust. In many nebulae, the formation of new stars is still happening and we can witness the formation of new open clusters.
M45 Pleiades
Probably the most famous open cluster, visible by the naked eye is called Pleiades, Subaru, or Seven Sisters. Charles Messier cataloged this DSO under number 45 (M45). This cluster is located in the constellation Taurus. It’s the closest cluster to the Solar system (430 light years), has 8 light years in diameter and it’s characterized by the nebulosity – reflective illumination of the space dust by the blue light of the hot, young stars. The brightest stars have names: Alcyone, Atlas, Electra, Maia, Merope, Taygeta, Pleione, Celaeno, and Sterope.
