|
Credit & Copyright: Albert Barr
Explanation:
Found among the rich starfields of the Milky Way toward the
constellation Cassiopeia,
star
cluster NGC 7789 lies about 8,000 light-years away.
A late 18th century
deep sky discovery of astronomer
Caroline Lucretia Herschel,
the cluster is also known as Caroline's Rose.
Its suggestive appearance is created by the cluster's nestled
complex of stars and voids.
Now estimated to be 1.6 billion years young, the
galactic or open cluster of stars also shows its age.
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 many red giant stars shown with a
yellowish cast in this lovely color composite.
Using measured
color and brightness, astronomers
can model the mass and hence the age of
the cluster stars just starting to "turn off" the main sequence
and become red giants.
Over 50 light-years across,
Caroline's Rose spans about
half a degree (the angular size of the moon)
near the center of the wide-field telescopic image.
|
January February March April May June July August September October November December |
| ||||||||||||||||||||||||||||||||||||||||||||||||
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: red giant - stellar evolution
Publications with words: red giant - stellar evolution
See also: