Rotational properties of the single-star model. Top: angular momentum J(m) within the mass coordinate m divided by m^5/3 as a function of m at different evolutionary stages for the primary star of the binary model examined in Sect. 4.3.1 (dashed) and its primary star as a single star (thick lines). The vertical black lines indicate the last calculated mass of the CO-core of the models. The thin dotted lines represent constant values of the angular momentum J: (from top to bottom) logJ/10⁵⁰ erg s = {1, 0, −1, −2, −3, −4}. Bottom: evolution of the angular velocity of the single-star model near the centre (coloured by the central helium mass fraction) and at the surface. The vertical lines indicate hydrogen depletion and helium ignition.