File:M57 (Ring Nebula) (noao-m57largeblock).jpg

English: The ring nebula is probably one of the most famous deep sky objects. Generally when amateurs begin their telescopic journey, after the Orion Nebula, the Ring is one of the next objects on the list. Even through a small telescope its bright and distinctive shape sets it apart from a typical field of stars. An image such as this, when acquired using a CCD camera, shows both the detail and color of this remarkable object. Like others of its type, the Ring Nebula is the expelled outer envelope of an aged star that has now reached its final stages of life. This bubble of gas is more than 2000 light years away and therefore is itself more than 1 lightyear in diameter. The white dwarf (central star which is the naked core of the original sun-like whole) is extremely hot (100,000K) and emits copious amounts of UV radiation. This emission excites various gases in the bubble and makes them glow (not unlike a neon light). The sphere of gas continues to expand, and if we could watch for the next 300,000 years the bubble would thin and disintegrate leaving the cold dark husk of the cooled white dwarf.Technically a better description of this "bubble" of gas is something a bit more cylindrical. In this case we are looking down the major axis (shaft) of the short tube. Previous episodes of mass loss can be seen in concentric layers far from the brightest portion. Please visit the NOAO M57 to see a similar picture created with the Kitt Peak 2.1-meter telescope. If we were able to look at the ring nebula from the side (rotate 90 degrees), it would look like M76. Also note the galaxy, IC 1296, which floats majestically in the background.This image was taken as part of Advanced Observing Program (AOP) program at Kitt Peak Visitor Center during 2014.