The Night Sky: Globular Star Cluster M13

The Milky Way Galaxy contains many different kinds of objects. Globular star clusters are among my favorite in the galactic zoo. Globular clusters are tightly packed with several hundred thousands of stars. They are always far from the disk of the galaxy. This is in stark contrast to open/galactic star clusters such as .

M13 Contains nearly half a million stars in an area about 150 light years across. It is 26,000 light years away in the constellation Hercules, and is one of many globular star clusters that orbit around the Milky Way galaxy. The stars of Globular clusters are 10 to 12 billion years old, and are thought to be the first stars to form during the formation of the Milky Way galaxy.

As seen in the picture taken at the Round Hill Observatory in Greenwich, the stars in the center of M13 are VERY close. They are in fact 500 times closer to each other than the stars near our Sun. The nearest star to our Sun is over 4 light years away, but there are over 100 stars inside a cube 3 light years wide in the center of the M13 star cluster.

Visually through a telescope, M13 looks like salt sprinkled on a dark background.  I always get a kick at realizing the light we see tonight left that star cluster over 26,000 years ago!

Clear
Skies!