Evolution of the product αβ of a 1.3 M_⊙ initial mass model from the PMS to the white dwarf stage. Symbols for the evolutionary phases: PMS (continuous line), main-sequence and thermally pulsing asymptotic giant branch (asterisks), “blue loops” (dashed line) and cooling sequence of white dwarfs (dots). The position of neutron stars is indicated by an open star. The corresponding HR diagram is shown in the left upper corner of the figure.