Owl Nebula

Located 2,030 light-years away in Ursa Major, the Owl Nebula is one of the larger planetary nebulae in the sky, spanning roughly 3 light-years across. It was formed when a Sun-like star shed its outer layers at the end of its life, leaving behind a hot white dwarf at its centre whose ultraviolet radiation causes the surrounding gas to glow. The two dark circular patches that give it its owl-like appearance are cavities of lower gas density aligned along the polar axis of the original star. At magnitude 9.9 it is a challenging but rewarding target from a light-polluted city sky, and the Dwarf 3’s narrowband capability helps cut through Edinburgh’s glow to reveal the subtle structure within the disc.