Our image of Messier
80 is actually a side-product. The night the image was taken, there were three
minor planets - Ceres, Dione and Katyusha - in the field of view, which were
the actual target of the image. In the upper right corner of the image there
are two small and faint galaxies, IC 4596 and IC 4600.
M 80 (Type II) is a small globular cluster in the
constellation of Scorpio and is located at a distance of about 33,000 light
years from the solar system. The true diameter is about 100 light years. The
age of the stars in the cluster is estimated at 13 billion years. The globular
cluster was discovered on January 4, 1781.
Unusual is the high number of blue stars, so called "blue stragglers"
in M 80. Such stars are usually located in regions with a high star formation
rate, which does not occur in old globular clusters. Astronomers believe that
these stars are formed when two smaller stars collide and merge. Such
collisions are virtually impossible in normal regions of a galaxy, but in
globular clusters the star density is thousands or tens of thousands of times
higher. M 80 is one of the densest globular clusters in our Milky Way.