Image neutronstar

Neutron stars

These bodies are the result of the evolution of stars with a mass that is slightly superior to that of the Sun. They are very small, as can be seen from the figure, which compares them to a white dwarf shown on the left.

The mass of a neutron star can be compared to that of the Sun but it is only the size of a big asteroid, with a diameter of about 30 kilometres. As a consequence, the density is huge: just think that a piece of neutron star, as big as a sugar-cube, weighs as much as all the people on our planet, six billion, put together.

These unusual stars are formed when their nuclei can no longer reach the temperatures necessary to trigger off another transformation process of the gas particles contained within it. The stars are unable to produce enough energy to oppose the contractions. The collapse continues until the same atomic nuclei break up and the protons fuse with the electrons, and form a sea of neutrons. Hence, the name neutron stars


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