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Дата индексирования: Mon Oct 1 21:25:40 2012
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Поисковые слова: cygnus

Ring Nebula

NGC 6720

Ring Nebula

M 57

RA 18:54; Dec 33:02 (Lyra)
Distance: 5000 ly
Type: planetary nebula
The Ring Nebula is the probably most famous planetary nebula, it is certainly a good example of the class.
Planetary nebulae are much, much smaller than diffuse nebulae and thus much more difficult to observe. The Ring Nebula is only about half a light-year across. (But, for perspective, that is roughly 500 times the diameter of the solar system.)
It has a relatively high surface brightness and so is somewhat easier to see with amateur equipment. The central star, however, is very dim.