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The "Dumbbell" Nebulaa Close Planetary Nebula
This planetary nebula was formed when an evolved, red giant star ejected its outer envelope near the end of its lifetime, when nuclear fusion stops in its core.. The expanding cloud of gas becomes visible once the hot core of the white dwarf star, visible near the center, is exposed and the high-energy, ultraviolet light from the core ionizes the cloud. This makes the nebula emit mostly a strong emission-line spectrum.
The Dumbbell nebula is about 850 light-years away from Earth and about 1.5 light-years in diameter. It is about 1000 light-years away in the constellation Vulpecula.
The Hubble Space telescope has taken a close-up picture of the Dumbbell Nebula.