نجم نيوتروني
Neutron stars that can be observed are very hot and typically have a surface temperature of around . They are so dense that a normal-sized matchbox containing neutron-star material would have a weight of approximately 3 billion tonnes, the same weight as a 0.5 cubic kilometre chunk of the Earth (a cube with edges of about 800 metres) from Earth's surface. Their magnetic fields are between 108 and 1015 (100 million to 1 quadrillion) times stronger than Earth's magnetic field. The gravitational field at the neutron star's surface is about (200 billion) times that of Earth's gravitational field.