Stargazing - 05.23.12 A “city” of hundreds of thousands of stars
passes high overhead on spring and summer evenings — the
globular cluster known as M13. It looks like a faint, fuzzy
point of light in the constellation Hercules. An ancient “city”
of stars passes high overhead on spring and summer evenings — a
globular cluster known as the Hercules Cluster, M13. It’s a
faint, fuzzy point of light in the constellation Hercules. The
cluster is about 25,000 light-years away, and it contains
hundreds of thousands of stars. But they’re crammed into a
region that’s only about a hundred light-years across, so the
cluster contains hundreds of times more stars than are found in
a similar volume of space around the Sun. Most of the stars in
globular clusters are red and faint — a strong indication that
they’re among the galaxy’s oldest stars. In fact, the stars in
M13 are probably at least 12 billion years old — close to three
times the age of the Sun. The stars in globulars are also
different from the Sun in another way