NGC 7789: Galactic Star Cluster
Explanation:
At 1.6 billion years old, this cluster of
stars is beginning to show its age.
NGC 7789 is an
open or galactic star cluster about 8,000 light-years
distant toward
the constellation Cassiopeia and lies near
the plane of our
Milky Way galaxy.
All the stars in the cluster were likely born
at the same time but the brighter
and more massive ones have more
rapidly exhausted the hydrogen fuel in their
cores.
These have evolved from
main sequence stars like the sun
into the gaggle of red giant stars
apparent (with a reddish-yellow cast)
in this lovely
composite color image.
Comparing computer models to observations of
the red giants and
main sequence stars
astronomers can determine the
mass and hence the age of the cluster stars just starting to
"turn off" the main sequence to become red giants.
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.
