Mass of the CO core (top) and radius (bottom) as a function of time, for two single HeS models (He2.97 and He2.83, in red and blue respectively) and one binary-stripped HeS model (B12.3p251 in black). In the top panel, $M_{\mathrm{conv},\mathrm{He}}^{\max }$ is shown with a dashed line for each model, and the moment of core C-ignition is highlighted with an arrow on top of the figure for each model. The models are plotted until the end of the first C-burning shell.