Sh2-202 is a bright emission nebula located in the constellation of Cassiopeia. It is part of a larger complex of star-forming regions and is known for its striking appearance, which is primarily due to the ionization of gas by nearby hot stars. The nebula is approximately 1,000 light-years away from Earth and spans several light-years in diameter. This nebula is often studied by astronomers to understand the processes of star formation and the dynamics of interstellar gas. Sh2-202 is also associated with the open cluster NGC 281, which contains young, hot stars that contribute to the nebula's luminosity.