M57, the Ring Nebula, is one of the most beautiful objects in the Northern sky. It was discovered by Antoine Darquier de Pellepoix in 1779. M57 is believed to be a planetary nebula, similar in structure to M27.

The Ring Nebula contains a central star, discovered by the German astronomer, F. von Hahn, in 1800. Observing the central star is one of the great challenges of amatuer astronomy. The star itself is a planet-sized white dwarf. The Ring Nebula was probably formed when this central star exploded long ago.