Neutron stars are: Low density star remnants with a mass less than the mass of the Sun.

Incredibly small remnants of supermassive stars where the gravitational collapse is halted by neutron degeneracy.

Incredibly big and massive star remnants that expel all neutrons in a supernova explosion. Neutron stars are:

The last option) This is because: A neutron star is the collapsed core of a giant star which before collapse had a total of between 10 and 29 solar masses. A neutron star has a mass of about 1.4 times the mass of the sun.

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