NS mass M and mass of the crust M_crust (inset) for the DH and NL3ωρ EOS as a function of the baryon central density n_c. Solid black curves indicate the exact solution calculated for the unified EOS (including the crust EOS), blue curves indicate the mass of the core (P>P_cc), and dashed (red) lines indicate the approximation based on Eq. (19), which were obtained using the core EOS alone.