Left panel: temperature gradients ∇_r, ∇_ad, and ∇_r−∇_Ω as function of the dimensionless radius R/R_⊙ according to the MKE model (blue curves) and the M1 model (pink curves) below the stellar surface. The black line denotes the radiative temperature gradient ∇_r in the model without rotation. The green line denotes the temperature gradients ∇_ad. The red curve indicates the quantity ∇_Ω. Right panel: various temperature gradients located at the border of the convective core. The point where black lines cut green lines implies the border of convective core in non-rotating model according to the Schwarzschild criterion. The point where blue lines cut green lines indicates the border of convective core in rotating model according to the Schwarzschild criterion.