Ring Nebula
From Wikipedia, the free encyclopedia.

The Ring Nebula in Lyra, also known as M57 or NGC 6720 is the most famous example of a planetary nebula. Located at 0.7 kpc (2300 light-years) from us, the nebula is illuminated by a white dwarf of 15.8 visual magnitude.

See also:

• Messier 57, SEDS Messier pages

The original article can be found at: http://en.wikipedia.org/wiki/Ring_Nebula.
All text is available under the terms of the GNU Free Documentation License.