Planetary Nebula NGC 7027 in Infrared
NGC 7027
is one of the smallest known
planetary nebulae.
Even so, NGC 7027 is 14,000 times larger than the Earth-Sun distance. Planetary nebula are so
named because
the first few discovered appeared similar to planets.
Planetary nebula
are actually dying stars, though, that have
recently run out of nuclear fuel.
The outer gaseous shells are expelled by an unknown process,
frequently creating
spectacular displays.
In the above picture in infrared light, the hot central star is visible. Our
Sun will become a
planetary nebula
in about 5 billion years.