Baryonic mass (M_b) and gravitational mass (M_g) as functions of the central energy density (ε_c) for a fixed angular momentum (J). The solid black line represents the gravitational mass, while the dashed black line represents the baryonic mass. Vertical gray lines mark the central energy densities at the onset (ε_c = 275 MeV/fm³) and completion (ε_c = 595 MeV/fm³) of the phase transition (PT). Black dotted lines and the blue-shaded region denote unstable configurations. The inset zooms into the PT region, illustrating the mass defect (ΔM_g) of 0.016 M_⊙ associated with the transition from hadronic to quark matter. The horizontal gray lines indicate constant values of M_b and M_g during the PT. The star marker denotes the birth mass of the twin star configuration at M_g = 1.499 M_⊙.