M81 in True Color
Explanation:
Here's what a spiral galaxy REALLY looks like.
Yesterday, M81 was shown in
two colors only, but here we see
M81 at its most
colorful. In
the above
picture, note how blue
the spiral arms are - this indicates the presence of
hot young stars and
on-going star formation.
Also note the yellow hue of the nucleus, possibly
designating a population of older stars many billions of years old.
M81
is actually a dominant member of a group of galaxies which includes
M82
and several other galaxies. Unlike our
Local Group of galaxies, large
galaxies in
the M81
group are
actually colliding. It is possible that
M81's interaction with M82 create the
density
waves which generate M81's
spiral structure.
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.
