Standard theories of stellar evolution hold that the position of a star on the Hertzsprung–Russell diagram should be determined almost entirely by the initial mass of the star and its age.
Standardne teorije zvjezdane evolucije drže da položaj zvijezda na Hertzsprung–Russellovu dijagramu trebao bi u gotovo u potpunosti biti određen početnom masom zvijezde i njenom dobi.