NGC 6164: A Dragon's Egg
Image Credit &
Copyright:
Daniel Stern
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 common and 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 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.
This gorgeous telescopic view
is a composite of extensive narrow-band image data,
highlighting glowing atomic hydrogen gas in red and oxygen in greenish hues,
with broad-band data for the surrounding starfield.
Also known as the
Dragon's Egg nebula,
NGC 6164 is 4,200 light-years away in the right-angled southern constellation
of Norma.