Example Kippenhahn diagram for a 2.00 M_⊙ star accreting 0.50 M_⊙ of material from a 2.50 M_⊙ AGB star at a metallicity of [Fe/H] = − 0.15. Green colors denote convective regions, and purple colors denote radiative regions, determined by the computed difference in the radiative and adiabatic transfer gradients. In the total mass on the y axis, the accretion phase can be identified by the increase in mass. The upper x axis shows log₁₀(Age/yr), and the lower x axis shows the model number, which is highly nonlinear with respect to time.