Bubble Nebula (NGC 7635), Northern Lagoon, and Cassiopeia's Cluster (M 52)

The Bubble Nebula (NGC 7635), also known as NGC 7635, is an emission nebula in the constellation Cassiopeia. It was formed by the stellar wind from the hot, massive Wolf–Rayet star SAO 20575. This star has an apparent magnitude of 8.7 and a mass of 10–40 solar masses. The Bubble Nebula is part of a giant molecular cloud located 7,100–11,000 light-years from the Sun. The Northern Lagoon is a star-forming region in the constellation Perseus, located about 1,000 light-years from Earth. It contains many young stars surrounded by clouds of gas and dust. Studying the Northern Lagoon helps astronomers better understand the processes of star and planetary system formation. The open star cluster M52 is located in the constellation Cassiopeia. It lies about 35 arcminutes from the Bubble Nebula. The cluster contains several dozen stars that formed at roughly the same time from the same cloud of gas and dust. Studying open star clusters helps astronomers understand the evolution of stars and galaxies.