Figure 12-22Model of a Neutron Star’s Interior This drawing shows the theoretical model of a 1.4 M_⊙ neutron star. The neutron star has a superconducting, superfluid core 9.7 km (6.0 mi) in radius, surrounded by a 0.6-km-thick (0.37-mi-thick) mantle of superfluid neutrons. The neutron star’s crust is only 0.3 km (0.19 mi) thick (the length of four football fields) and is composed of heavy nuclei and free electrons. The thicknesses of the layers are not shown to scale.