Explanation:
NGC 6888, also known as the Crescent Nebula, is a
cosmic bubble about 25 light-years across, blown by
winds from its central, bright, massive star.
This
beautiful portrait of the nebula is from the
Isaac Newton Telescope at
Roque de los Muchachos
Observatory in the Canary Islands.
It combines a composite color image
with narrow band data that isolates light from hydrogen
and oxygen atoms in the wind-blown nebula.
The oxygen atoms produce the blue-green hue that seems to enshroud
the detailed folds and filaments.
NGC 6888's central star is classified as a
Wolf-Rayet star
(WR 136).
The star is shedding its outer envelope in a strong
stellar
wind,
ejecting the equivalent of the Sun's mass every 10,000 years.
The nebula's complex structures are likely the result of this
strong wind interacting with material ejected in an earlier phase.
Burning fuel at a prodigious rate and
near the
end
of its stellar life this star should ultimately go out with a bang in a
spectacular supernova explosion.
Found in the nebula rich
constellation Cygnus,
NGC 6888
is about 5,000 light-years away.
digg_url ='http://apod.nasa.gov/apod/ap090915.html'; digg_skin = 'compact';
