What is a neutron star?
A neutron star is the collapsed core of a giant star which before collapse had a total mass of between 10 and 29 solar masses. Neutron stars are the smallest and densest stars, not counting black holes, hypothetical white holes, quark stars and strange stars.
As a star runs out of fuel it will eventually collapse in upon itself. In the formation of a neutron star, the protons and electrons within every atom are forced together, forming neutrons. Material that is falling to the centre of the star is then crushed by the intense gravitational forces in the star and forms this same neutron material.
The gravitational forces in a neutron star are also incredibly strong. The matter is so densely packed together into a radius of 20 kilometres (12 miles) that one teaspoon of mass would weigh up to a billion tons, about the same as Mount Everest. They also spin up to 600 times per second, gradually slowing down as they age.
In fact, if you were able to drop an object from a height of one metre on the surface of a neutron star, it would hit the ground at about 2,000 kilometres (1,200 miles) per second.
