The Three Faces of the Ring Nebula -- NGC 6720
The top image is what we usually see in pictures of the Ring Nebula.
The second image is a deeper exposure, revealing loops and filaments just outside the "ring" of the Ring Nebula.
Very deep exposures, like that shown in the third image reveal a nearly perfectly circular halo of glowing material surrounding the Ring Nebula and its loops.
All 3 of these images were taken from a single CCD exposure, but displayed at 3 different contrast levels. All have the same identical scale, so you can see the small size of the piece we normally think of as "The Ring".
In the bottom image, the 3 images have been put back together using an image processing technique that allows the 3 components to be more visible. This image is displayed in negative since more detail is seen this way.
The latest image of the "ring nebula" taken by the WIYN 3.5m Telescope can be seen by clicking on the magnifying glass.
Shape: Also known as M 57 , this PN, although not perfectly round, has a distinct ring shape.
Distance: approx. 2,000 light years
Location: Lyra constellation
RA: 18 53 35.16 DEC: +33 01 43.2
Size: 2.5 (arc minutes) in diameter (central bright ring)
Abundances/Description: mostly apparent is the greenish light from ionized oxygen. The red part of the ring has is due to emission from ionized Hydrogen and nitrogen.
Discoverer: Darquier (1779)