Spiral Galaxy NGC 1232
Explanation:
Galaxies are fascinating not only for
what is visible, but for what is invisible.
Grand
spiral galaxy
NGC 1232,
recently captured in detail by the new
Very Large Telescope,
is a good example.
The visible is dominated by millions of
bright stars and dark
dust,
caught up in a gravitational swirl of
spiral arms rotating about the center.
Open clusters containing
bright blue stars can be seen sprinkled along these spiral arms,
while
dark lanes
of dense interstellar
dust
can be seen sprinkled between them.
Less visible, but detectable, are billions of dim normal
stars and vast tracts of
interstellar gas,
together wielding such high mass that they
dominate the dynamics of the inner
galaxy.
Invisible are even greater amounts of matter
in a form we don't yet know - pervasive
dark matter needed to explain the
motions of the visible in the outer galaxy.
What's out there?
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.
