Sharpless 2-3 is a bright emission nebula located in the constellation of Cassiopeia. It is part of a larger region of star formation and is approximately 2,500 light-years away from Earth. The nebula is known for its striking colors, primarily due to the ionization of hydrogen gas by nearby hot stars. This nebula is also associated with the open cluster NGC 281, which contains young, massive stars that contribute to the nebula's luminosity. Sharpless 2-3 is often studied by astronomers to understand the processes of star formation and the dynamics of interstellar gas.