Kippenhahn diagrams for the NOV (left) and OV (right) σ = 0.0 models. The x-axis is the respective stellar model’s age, the left y-axis is the mass coordinate, the right y-axis is the central mass fraction of the isotopes. Bright green areas represent convection, blue shaded regions depict nuclear burning (see color bar), white areas represent radiation, and yellow-gold areas represent overshooting (right figure). The light green area shows the hydrogen envelope. The solid pink curve is the central ⁴He mass fraction, the solid dark blue curve is the central ¹⁶O mass fraction, and the dark yellow curve is the central ¹²C mass fraction. The dashed line shows core helium depletion. The evolution was terminated when ﹩\mathrm{log}(L/{L}_{\odot })\gt 3.0﹩ for all stellar models, and the figures are plotted until that point. Annotated is the radiative R2 region’s edges and widths. An interactive figure is provided in the online version. Its functionality compares the NOV and OV Kippenhahn diagrams for any given σ _i ¹²C(α, γ)¹⁶O reaction rate. To use the interactive figure, click on the “sigma” slider at the top, and slide through the indices 0 through 12. Sliding through each index provides the user the side-by-side comparison of the Kippenhahn diagrams for the respective σ _i ¹²C(α, γ)¹⁶O reaction rate used in the evolution. Index 0 starts at σ _−3.0 and index 12 ends at σ _3.0.

An interactive version of this figure is available in the online journal.