Explanation:
This pretty planetary nebula, cataloged as
NGC 6369, was discovered
by 18th century astronomer
William
Herschel as he used a
telescope to explore the medicinal constellation
Ophiucus.
Round and planet-shaped, the nebula
is also relatively faint
and has acquired the popular moniker of
Little Ghost Nebula.
Planetary
nebulae in general are
not at all related to planets,
but instead are created at the end of a sun-like star's life as its
outer layers expand
into space while the star's core shrinks to become
a white dwarf.
The transformed white dwarf star,
seen near the center,
radiates strongly at ultraviolet wavelengths and powers the expanding
nebula's glow.
Surprisingly complex
details
and structures of NGC 6369 are revealed in
this
tantalizing image
composed from Hubble Space Telescope data.
The nebula's main ring structure is about a light-year across and
the glow from ionized oxygen, hydrogen, and nitrogen atoms
are colored blue, green, and red respectively.
Over 2,000 light-years away, the
Little Ghost Nebula offers a glimpse
of the fate of our Sun, which could produce its own planetary
nebula only about 5 billion years from now.
