Astronomy Picture of the Day: 11/05/13 - The Omega Centauri Globular Cluster

Want to take a guess at how many stars you"re looking at in this small patch of space? This bit of space, which is a part of the larger Omega Centauri globular cluster (the largest of the star clusters located in the Milky Way galaxy), contains over 100,000 stars. This is an astonishingly large number of stars lurking in an area that spans only 150 light-years across. It"s even more astonishing to learn that 100,000 is only a small fragment of stars compared to the total number found in this dense cluster, around 10 MILLION.

With the holiday season right around the corner, this cluster kind of sets the mood? The contrast of coloring within the densely-packed stars in the cluster is largely due to collisions and mergers, which can transform two dim red-dwarves into one massive bluish-white star. There are also quite a few sun-like stars seen here, but by far, red is the most prevalent color, indicating this cluster is quite old. Maybe around 12 billion years in age.

There are about 150 known globular clusters within the Milky Way galaxy. All of these clusters are thought to be among the oldest objects in the galaxy, filled with older, less massive-than-our-sun red-dwarfs that may be entering the red-giant phase of stellar evolution. Understanding their properties helps astronomers pin down important information about the galaxy"s history, along with the age of the universe in general. This one in particular, Omega Centauri, is located about 15,000 light-years from Earth in the constellation known as Centaurus.

References, sources, and further reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-110513-the-omega-centauri-globular-cluster/