Sh2-121, also known as LBN 762, is a bright emission nebula located in the constellation of Cygnus. It is part of a larger molecular cloud complex and is approximately 1,500 light-years away from Earth. The nebula is characterized by its vivid colors, which are produced by ionized gases, primarily hydrogen. This nebula is often studied by astronomers to understand star formation processes. The intense radiation from nearby young stars excites the surrounding gas, causing it to glow. Sh2-121 is a fascinating example of the dynamic interactions between stars and their surrounding environments in the universe.