NGC 7635, also known as the Bubble Nebula, is an emission nebula in the constellation Cassiopeia. It is located about 7,100–11,000 light-years away and was formed by the stellar wind from a massive O-type star, BD+60°2522. The "bubble" shape arises due to the interaction of the star's intense wind with surrounding molecular clouds. The nebula is part of a complex region of gas and dust, and its bright, ionized hydrogen glows red due to ultraviolet radiation from the central star.

M52 is an open star cluster, also in the constellation Cassiopeia, located approximately 5,000 light-years away. It contains several hundred stars and is estimated to be around 35 million years old. The cluster is rich in stars, including a few yellow giants, and appears tightly packed when viewed through a telescope. It is often noted for its beauty and the contrast of its stars against the backdrop of the Milky Way. M52 lies near the Bubble Nebula, though the two are not physically connected as M52 iies in the foreground by several thousand  light years.