Sh2-173 is a bright emission nebula located in the constellation of Cassiopeia. It is part of a larger region of star formation and is known for its striking appearance, which is primarily due to the ionization of gas by nearby hot stars. The nebula is approximately 2,500 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. Sh2-173 is also associated with the LBN 762 dark nebula, which is a region of dense dust that obscures light from stars behind it, creating a contrast with the bright emission of Sh2-173.