Globular Clusters are a collection of stars that are gravitationally bound together. Generally spherical in shape, GC's may contain anywhere from tens of thousands to millions of stars. They are very tightly packed when compared to star densities found in the main galaxy. They are found not only in our own galaxy but have been found in others.
The origin of GC's remains unknown. The stars in the cluster are some of the oldest stars known suggesting they existed at the start of the host galaxy but there is no evidence the two formed together. It is thought that a black hole exists at the heart of many clusters. The orbits of GC's are also interesting. Not only are they large, existing some 130,000 light years from the galactic center, but they do not lie in the galactic plane. Sort of like a group of buzzing bee's.
The pictures I have posed here are my best efforts but honestly no picture I have ever seen does justice to the impressive objects. When you see them through a nice telescope with you own eyes these are breath taking.
Discovered in 1746 by Jean-Dominque Maraldi and included in ars fCharles Messier's famous catalog. Located 33,000 light years from earth in the constellation Pegasus and it's age is estimated to be 13.6 billion years old! That is old. It contains one of only four know planetary nebula found in a globular cluster.