2 Globular Clusters
Globular clusters comprising 
to 
stars were formed early in the history of the Milky Way, and
are scattered throughout the halo. The age of the clusters is about 13 Gyr, with an age spread of less than
5 Gyr [31]. According to the frequently updated catalog of globular cluster properties maintained on the
web by Harris [95
], the globular cluster system numbers roughly 150 clusters. Although the list is fairly
complete, new globular clusters have been recently discovered at very low galactic latitudes [114, 135], and
there is the prospect for a few more clusters to be hidden behind the bulge or out in the far reaches
of the galaxy. The distribution of globular clusters in galacto-centric coordinates is shown in
Figure 1.
.
