Explanation:
Appropriately nicknamed
"the Skull Nebula",
planetary nebula NGC 246 really does surround a
dying star some 1,600 light-years away in the constellation
Cetus.
Expelled over a period of thousands of years,
the lovely, intricate nebula is the outer atmosphere of a
once sun-like star.
The expanding outer atmosphere
is interacting with the gas and dust in the
interstellar medium,
while the star itself, the fainter member of the binary
star system seen at the nebula's center, is entering its
final phase
of evolution, becoming a dense, hot
white dwarf.
Star and nebula are moving rapidly toward the top of
the detailed view, as suggested by the nebula's brighter,
upper, leading edge.
The sharp image spans just over 2.5 light-years at
the estimated distance
of
NGC 246 and also reveals distant
background galaxies, some visible right through the nebula
along the bottom.
