Thermal luminosities vs. ages of isolated neutron stars. The same color coding as in Fig. 1 is used (in addition to PSR J0726–2612, the three High-B pulsars are J1119−6127, J1718−3718 and J1819−1458). The solid and dashed lines are the theoretical cooling curves of a neutron star with mass M = 1.2 M_⊙ and the dipole magnetic field of PSR J0726–2612 (B_p = 6 × 10¹³ G), with the heat blanketing outer envelope composed either of iron (solid line) or of accreted light elements (dashed line).