IC 4406: A Seemingly Square Nebula
Explanation:
How can a round star make a square nebula?
This conundrum came to light with the discovery of
planetary nebulae like IC 4406.
IC 4406 is most probably cylindrical,
with its square appearance the result of our
vantage point in viewing the cylinder.
Hot gas is
known to be flowing out the ends of the cylinder,
while filaments of dark
dust and
molecular gas
lace the bounding walls.
The star primarily responsible for this
interstellar sculpture can be found in the
planetary nebula's center.
In a few million years, the only thing left visible in
IC 4406 will be a fading
white dwarf star.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
