A Neutron star is a star which has ceased nuclear fusion. As nuclear fusion does not take place, thermal pressure is overcome by gravity and the star starts to collapse. The pressure than pushes protons and electrons together to form neutrons and it further collapses due to the Pauli exclusion principle.The star will stop collapsing once the neutron degeneracy pressure equals to gravity, thus, achieving electrostatic equilibrium. However, only stars of mass less than 1.44 solar mass becomes a Neutron star. Neutron stars have a very strong gravitational strength, are compact in size, and are very hot.