Neutron-degenerate matter

Neutron-degenerate matter is a type of matter made up of many small pieces called neutrons. Neutrons are particles that actually don't have any electrical charge, so they can stick together very tightly and form a very dense material. This matter is so dense that even though it takes up a small amount of physical space, its mass is very, very large. Neutron-degenerate matter is very hard to find because it is so small and so dense. It is usually only found in very extreme places like the centers of very large stars.