I think I have not told anything about neutron stars and has reached the right time to do so.
You know that there are many types of stars, in fact, when you talk about the classification (one) I said that according to its color and size so were named.
Color and size are the general characteristics of a star, like the light emitted (frequencies) that help us know “that this made” the star.
He will also talk about “life” of a star, indicating the stages through which it passes from birth (condensation) to “death” through different kinds of lives.
One of these lives end of a star is to become a neutron star.
In these stars, after they have lost the outer layers and gravity is stronger than love (meaning that electrical repulsion and the strong forces of atoms) the core, the star (because little there is) is a dense soup particles. Fortunately, the strong forces of the atoms get even fight extreme gravity and do not reach the next stage of star, a quark star.
The fact is that the star consists of a soup or uncharged particles. If they charge (ie, there is a bit of everything) we have a white dwarf, but if a white dwarf is composed of something without charge (neutrons) have a neutron star.
Remember, a neutron star is but a soup of neutrons by the Pauli exclusion principle, not put one above the other. The Pauli exclusion principle only tells us that there can be a system, two fermions with the same quantum state, ie, in the end, the repulsion or strong force is still there preventing neutrons collapsing into something more “fluid” and that elementary particles (fermions) have a power, almost all.
Neutron stars (which are not so rare) have certain characteristics that, voice suddenly and primary physical, can see.
As you know, the stars (such as planets) rotate on its axis, then, on the surface (eg Earth) there is a thing called angular momentum is the speed that the distance to the axis of rotation. This angular momentum is constant and therefore the Earth always rotates at the same speed.
The stars, as I said, also have angular momentum and this is constant. So if we calculate the angular momentum of a neutron star that comes from a fat star, this must be constant and as the offset is much less we … oh surprise, rotating at lightning-fast speeds.
This, which rotate at high speeds, coupled with that, as we know, as a star, shoot energy outward, gives an effect called “lighthouse”. That is, neutron stars are easy to spot because they are like beacons of electromagnetic waves due to its rotation speed. That is why they are called “pulsars“.
This is the most curious things neutron stars, which, if you’re interested, I recommend and I encourage you to read about them.