Messier 27 is
considered by many to be the finest planetary nebula in the sky. It is
certainly one of the largest and easiest to observe in an amateur
telescope. When observed through the eyepiece of the typical
amateur telescope, this object appears as a large disk that is pinched
in on its east and west sides, thus the common name of the "Dumbbell
Nebula". Messier 27 is estimated to be approximately 1.5 light years
wide [easily encompassing our entire solar system]. Various
estimates place the age of the nebulosity at between 3,000 and
48,000 years old.
The nebulosity, which is the visible part of Messier 27, was
created from the central star visible in this image when the star expend the
hydrogen fuel at its core. It entered a "giant" phase where
its outer layers expanded and the star ejected up to 25% of its total
mass. Planetary nebula can be composed of several shells of expanding
gas. The visible part of Messier 27 is an expanding shell of stellar
material that is set aglow by the central star which has since become a very
strong source of ultraviolet radiation. The central stars of planetary
nebula are among the hottest stars known.
More on Messier 27 and
planetary nebula in general can be found at:
http://www.seds.org/messier/m/m027.html
The upper image is a low
resolution full frame image. The lower image is at full
resolution and cropped.
