ABSTRACT
The dating of stars became possible beginning with developments in the 1920s when the source of stellar energy was identified by A. S. Eddington, Robert d'Adkinson, F. Houter- mans, and others as the conversion of hydrogen to heavier chemical elements in nuclear reactions in the interiors of the stars. Stars in the compact globular clusters that exist in our galaxy have the faintest turnoff luminosities known. There was a time in the history of the universe before either stars or galaxies existed. A principal problem in stellar and galactic evolution is to date the formation of the oldest stars in our galaxy. The compact globular clusters were the first aggregates to form in the galaxy as it collapsed from a larger volume when the protogalaxy that became the Milky Way decoupled from the general expansion of the universe. Stars in the compact globular clusters that exist in our galaxy have the faintest turnoff luminosities known.
