M57, the Ring Nebula, is a shell of gas surrounding a white dwarf star. The hot white dwarf star radiates ultraviolet light which excites the gases in the shell, causing them to glow in visible light. This image is very close to what a backyard astronomer sees as he looks through the eyepiece of his telescope.

The nebula is located in the constellation Lyra, which is high overhead in the late hours of a summer night.