Neutron stars

Origin and Facts on Neutron Stars

Neutron stars are the second most dense stellar objects in our universe, the first one being black holes, of course. As the name suggests, these type of stars are completely made out of neutrons and neutrinos and possess a powerful gravitational pull. They usually appear as the most powerful and bright pulsars out in the universe due to their rapid spinning. They are the smallest stars in terms of size.

How are neutron stars formed?

When a star that possess mass over 1.4 solar masses 

(surpassing the Chandrasekhar limit) would end up collapsing into a neutron star. A star that has about 8 times the mass of our sun would start fusing into iron, which is the last and heaviest element  to be made in a star. Beyond iron, for any further fusion to occur, it would require energy since it'd be an endothermic reaction.

Neutron stars do fuse till iron and will have iron deposits in their core which will further increase the density of their core. Due to this increase in density, the star will have a strong inward gravitational pull to itself. The presence of high temperatures in their core causes the protons and electrons to form neutrons and neutrinos. This increase in mass will contract the star furthermore and will result in a supernova explosion and will leave  a neutron star as it's remnant.

Neutron Degeneracy Pressure

Even after all of this chaos with density and contraction, why doesn't a neutron star completely collapse into black hole? There should be something that stops it halfway through. Yes, that's what we call the neutron degeneracy pressure . It is analogous or similar to the electron degeneracy pressure, only it's just neutrons instead of electrons. Due to the inward collapse of the core, all the neutrons are forced to occupy a decreasing area. This creates an outward  pressure  which actually opposes the contraction of the core. This is what we call neutron degeneracy pressure.

Apart from all these facts, they shine brighter than any larger normal stars in the universe and spin to about a hundred time in one second. They draw up all kinds of electromagnetic radiation like bright X-rays from nearby celestial objects by heating them up. They are associated with powerful magnetic fields, which is another reason why most of it's glowing radiation is concentrated near it.