Explanation:
Beautiful emission nebula NGC 6164
was created by a rare, hot, luminous
O-type
star, some 40 times as massive as the Sun.
Seen at the center of the cosmic cloud, the star is a mere
3 to 4 million years old.
In another three to four million years the massive star will end its life
in a supernova explosion.
Spanning around 4 light-years,
the nebula itself
has a bipolar symmetry.
That makes it similar in appearance to more familiar
planetary
nebulae - the gaseous shrouds
surrounding dying
sun-like stars.
Also like many planetary nebulae, NGC 6164 has been found to have
an extensive, faint halo,
revealed in this deep telescopic image of the region.
Expanding into the surrounding
interstellar medium,
the material in the
halo is likely from an earlier active phase of the O star.
The gorgeous skyscape
is a composite of narrow-band image data
highlighting the glowing gas, and broad-band data of the surrounding
starfield.
NGC 6164 is 4,200 light-years away in the southern constellation
of Norma.
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