- Object produced by the death of a star weighing 1.4–2.3 solar masses. As soon as there is too little radiation emerging from stars of this mass to prevent their collapse, they shrink until the pressure between neutrons in the star’s atomic nuclei will not allow them to become any smaller. neutron stars are still able to emit energy, as observations of pulsars confirm.
- A star whose mass greater than the sun, yet whose diameter is just a few kilometers, making it extremely dense. It consists mostly of neutrons, and an example is a pulsar.