Final answer:
Neutron stars are the densest objects in the universe and are composed mostly of neutrons. Their small size and rapid rotation are key characteristics. If a neutron star reaches its mass limit, it would continue to collapse and potentially become a black hole.
Step-by-step explanation:
Neutron stars are the densest objects in the universe, with a force of gravity at their surface 1011 times greater than what we experience on Earth. They are composed mostly of neutrons, with a small number of protons and electrons mixed in. Neutron stars have a diameter of only 10 to 20 kilometers, making them much smaller than a typical star.
There is no exact maximum mass limit for a neutron star, but calculations suggest it would be around 3 times the mass of our Sun. If a neutron star were to exceed this limit, it would continue to collapse further and become something even more compressed, such as a black hole. Neutron stars also have a fast rotation due to their small size, with one full spin taking only a fraction of a second.
The consequences of a neutron star reaching its mass limit would be the collapse into a more compact object, potentially a black hole. This collapse is caused by the inability of neutron degeneracy to stop the core from collapsing further. The collapse of a high-mass star's core into a neutron star leads to the rest of the star being blown apart in a type II supernova explosion.