Question

what is a neutron star ?

Answer 1

neutron star is a celestial object of very small radius (typically 30 km) and very high density, composed predominantly of closely packed neutrons. Neutron stars are thought to form by the gravitational collapse of the remnant of a massive star after a supernova explosion, provided that the star is insufficiently massive to produce a black hole.

Answer 2

it is so does your body which is very small and have high density