The Ring Nebula can be seen in early summer into winter and is easily located. M57 lies just below Vega in the summer triangle with Altair and Deneb in the constellation Lyra. M57 is about 1500 light years from Earth.

The star at the center of the Ring nebula has a surface temperature of 216,000 degrees Farenheit or 120,000 degrees Celsius. Our own star, the Sun, is expected to undergo the same process in a couple of billion years. Planetary nebulae do not last long at all in cosmic terms, the shell of gas expands and diffuses, becoming invisible, and the star turns into a white dwarf

Planetary nebula are shells of gas shed by stars late in their life cycles after using up all of their nuclear fuel. The star then ejects a significant portion of its mass in a gaseous shell, which is illuminated by its extremely hot central star, which is just the core left from the original star.

This widefield image was taken with a Canon 40D DSLR fitted with a light pollution filter and 8" F/5 Ritchey Cretien Astrograph. Exposure settings are 22 x 3mins @ ISO 1600 captured in Nebulosity, aligned and stacked. Image saved as a Tiff file and processed in Photoshop CS5. Image below is a cropped and enlarged.