Explanation:
What is creating the strange texture of IC 418?
Dubbed the
Spirograph Nebula for its resemblance to drawings from a
cyclical drawing tool,
planetary nebula IC 418 shows
patterns
that are not well understood.
Perhaps they are related to chaotic
winds from the variable central star, which
changes brightness unpredictably in just a few hours.
By contrast, evidence indicates that only a few million years ago,
IC 418 was probably a well-understood star similar to our
Sun.
Only a few thousand years ago,
IC 418 was probably a common
red giant star.
Since running out of
nuclear fuel, though, the outer envelope has begun
expanding outward leaving a hot remnant core destined to become a
white-dwarf star, visible in the
image center.
The light from the central core excites surrounding
atoms in the
nebula causing them to glow.
IC 418 lies about 2000
light-years away and spans 0.3 light-years across.
This false-color image taken from the
Hubble Space Telescope
reveals the unusual details.
