The Ring Nebula (also known as NGC 6720) is a planetary nebula in the northern constellation of Lyra. Such objects are formed when a shell of ionized gas is expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf.
Images by Gordon Collins
Images by Martin Crow
Images by Simon Dawes
Images by Debra Holton
Images by Keith Rickard
Images by David Sheehan
Images by Julian Tworek
Images by Andrew Wilson
