Sh 2-1, also known as Sharpless 2-1, 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 notable for its distinct shape and vibrant colors, which are produced by ionized gases. This nebula is often studied by astronomers to understand the processes of star formation and the dynamics of interstellar matter. Sh 2-1 is associated with a cluster of young stars, which contribute to the illumination and ionization of the surrounding gas, creating the stunning visual features observed in images.