In stellar evolution calculations, the local pressure scale height is often used to empirically constrain the amount of convective core overshoot. However, this method brings unsatisfactory results for low-mass stars (≤1.1–1.2 M⊙ for Z = Z⊙), which have very small cores or no convective core at all. Following Roxburgh's integral constraint, we implemented an upper limit of overshoot within the conventional method of α parameterization to remove an overly large overshoot effect on low-mass stars. The erroneously large effect of core overshoot due to the failure of α parameterization can be effectively corrected by limiting the amount of overshoot to ≤15% of the core radius; 15% of the core radius would be a proper limit of overshoot, which can be implemented in a stellar evolution code for intermediate- to low-mass stars. The temperature structure of the overshoot region does not play a crucial role in stellar evolution since this transition region is very thin.
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