Left panel: schematic EOS with a density jump phase transition on the pressure P–baryon density n_b plane. Right panel: gravitational mass M–radius R sequence of solutions in the case of a strong (destabilising) phase transition. We show the characteristic masses in this situation: the mass at the phase transition density M_ph, the maximum mass M_max, and the minimum mass M_min at the end of the instability (decreasing part of M(R) between M_min and M_ph indicated with a dotted line). Stable configurations between the M_max and M_min are sometimes called the twin branch.