An extremely dense star formed when a giant star called a supernova explodes.
An extremely dense star formed when a giant star explodes in what is called a supernova. Neutron stars may have twice the mass of our Sun, but are only a few kilometres in diameter. Their gravity is so strong that the star's atoms are squeezed into a soup of particles, with protons and electrons being squashed together to form neutrons.
Neutron stars may have twice the mass of our Sun, but are only a few kilometres in diameter. Their gravity is so strong that the star's atoms are squeezed into a soup of particles, with protons and electrons being squashed together to form neutrons.