Neutron Stars

Neutron stars are the final stage of a medium-high mass star. They come about after a medium-high mass star ends in a violent Supernova Type II explosion. What exactly are neutron stars?

Neutron stars are a second type of degenerate stars, much like white dwarfs. However, unlike white dwarfs, the degeneracy comes from neutrons, not electrons, hence the name. But neutron degeneracy only arises when the neutrons are much more closely packed than the electrons. Whereas a white dwarf is on the scale on the Earth, in terms of radius, neutron stars are only 10 km in diameter, about as big as the size of Manhattan Island. Masses for neutron stars are larger than the Chandrasekhar limit, but only goes up to two (2) solar masses. Anything larger than that, gravity breaks the neutron degeneracy, and the neutron star will collapse into a black hole, which is ever wackier.

Neutron stars can also spin rapidly, and if they are aimed correctly, they can beam jets of energy along magnetic field lines towards Earth. When we see a neutron star rotating in this manner and we detect the beam of energy, the neutron star is called a pulsar, even though the star does not pulsate. The beams of energy are similar to a lighthouse shining light out to the ocean at regular intervals. However, pulsars rotate so fast that they can have periods on the scale of milliseconds (rotating almost a thousand times a second). We will talk more about pulsars in the next post.