Question

Neutron stars are one of the possible “final states” of a star. The idea is that for a sufficiently massive star, the gravitational pressure is enough to overcome the outward pressure (that comes from essentially the Pauli exclusion principle) that keeps fermions from coinciding with each other.

Part A) According to quantum statistics, the OUTWARD pressure of a (neutron) fermionic gas is given by P=[(3.9?^2)/(2m)](N/V)^(5/3), where m is the mass of a neutron, and N/V is the number density of the neutrons. Set the two pressures (outward and inward) equal to derive an equation for the volume of a neutron star as a function of its mass.

Part B) What would be the radius of a neutron star which had twice the mass of our Sun? Compare its density with the density of a nucleon and of a nucleus.

Answer 1