Notes. The table summarizes key pre-SN properties for each He star model with the same initial parameters, including MESA’s default ¹²C(α, γ)¹⁶O rate from the NACRE compilation (Angulo et al. 1999), an initial metallicity of Z = 0.02, and a convective overshooting parameter of f_ov = 0.01. Column (1): Initial He star mass, $M_{\mathrm{He}}^{\mathrm{i}}$, (the 65 M_⊙ model experiences a weak PPISN); Column (2): CO core mass, M_CO, defined as the maximum mass coordinate where the central ⁴He mass fraction, X_He, drops below 10⁻¹ at the end of core He-burning, following Tauris et al. (2015); Column (3): Central ${}^{12}\mathrm{C}$ mass fraction, X_C, at the end of core He burning, defined as X_He < 10⁻⁴; Column (4): Carbon-free core mass, M_{C − free}, defined as the maximum mass coordinate where the central ${}^{12}\mathrm{C}$ mass fraction, X_C, is less than 10⁻⁵; Column (5): Compactness, ξ_2.5, (defined by Eq. 4); Column (6): Radial mass derivative, μ₄, (as defined in Eq. 5); Column (7): Mass coordinate, M₄, at a specific entropy of s = 4; Column (8): Central specific entropy, s_c, at the onset of iron-core collapse; Column (9): Final pre-SN mass, M_f; Column (10): Iron core mass, M_Fe; Column (11): Gravitational binding energy, −E_bind, of the material above the iron core (see also Temaj et al. 2024); Column (12): Explosion energy E_exp; Column (13): Predicted final fate of the star; Column (14): Gravitational compact remnant mass, M_{rm,  grav}. Both the predicted final fate, E_exp, and M_{rm,  grav} are derived from the semi-analytic model developed by Müller et al. (2016).