NGC 2403 is a prominent spiral galaxy located in the constellation Camelopardalis, approximately 10 million light-years from Earth. As a member of the M81 Group, NGC 2403 shares similarities with the nearby Andromeda Galaxy (M31), including its spiral structure and rich star-forming regions. This galaxy is noted for its numerous H II regions, which are large clouds of ionized hydrogen where new stars are born, making it a vibrant and active site of stellar formation.

One of the most striking features of NGC 2403 is its well-defined spiral arms, which are adorned with clusters of young, hot stars and bright nebulae. These features make NGC 2403 an excellent subject for studying the processes of star formation and the dynamics of spiral galaxies. Additionally, NGC 2403 has been the site of several supernovae, most notably SN 1954J and SN 2004dj, providing valuable data on the life cycles of stars and the chemical enrichment of galaxies. Its relative proximity and brightness allow astronomers to study its properties in great detail, enhancing our understanding of spiral galaxy evolution.