Neutron stars are compact city-sized cores that remain after a star explodes in a supernova. Neutron stars are tiny compared to the star that formed them because the matter that composes them is extremely dense and has special properties. This article explores some aspects of this special type of matter that composes neutron stars, giving astronomers new insights into the structure of these small, dense bodies.
http://www.raa-journal.org/raa/index.php/raa/article/view/423