What exactly is a neutron star?

Answer 1

A neutron star is a stellar body that is so dense that the interior gravitational pressure breaks apart atoms and creates a solid mass of neutrons. Since gravity is the weakest of the fundamental forces and the strong nuclear force is the strongest, that gives you some idea of how incredibly dense a neutron star must be for gravity to overcome the strong nuclear force.

A neutron star is created when a star slightly more massive than the Sun (1.35 to 2.1 times its mass) collapses. A less massive star lacks the mass for gravity to collapse it to this extent. A more massive star doesn't stop at being a neutron star but collapses into a singularity, a black hole.

Answer 2

A neutron star is the result of a 2 to 3 solar mass white dwarf about 100 km in diameter.
If it accretes enough matter the electrons and protons are forced together,the entity collapses to about 12 km in diameter.
The neutron star is made up of about 10 to the power of 56 neutrons each separated from the other by one half the diameter of a neutron.
A neutron star can collapse but only to about 6 km in diameter.
This puts all the neutrons in contact with each other and there is no space left to be displaced to allow the neutron star to collapse farther.
What happens to a neutron star after this is a very controversial issue.

Answer 3

Neutron Star, rapidly spinning, extremely dense astronomical object. Neutron stars are composed primarily of neutrons, minute, neutrally charged particles that exist in the nuclei of atoms. A neutron star is created when the core of a supergiant star—a massive star that has evolved so that it burns heavy elements instead of hydrogen—has converted all of the material in its core to iron. At this stage, no further nuclear reactions can take place to liberate energy, and so the core collapses under the mutual gravitational attraction of its own matter

Answer 4

It's a star's core. It's made of heavy particles called neutrons. A spoonful of it is the same weight as a heavy truck. When a massive star explodes, you got a black hole or a neutron star.

Answer 5

A neutron star is the collapsed core of a giant star that exploded as a supernova. Stars more than about 8 times the Sun's mass can fuse carbon and heavier elements. As it uses sucessively heavier elements, the core contracts further and the temperature and pressure rises higher to fuse the next heavier element for energy. This results in each element lasting for a shorter and shorter period before it's exhausted. However, this cannot go on indefinitely, because once the star's core is converted to iron, the end is at hand. Iron nuclei are so stable, any attempt to fuse or fission them takes more energy than the reaction releases. When the core attempts to fuse iron, fusion stops and the core implodes violently that the interior of an exploding H-bomb. The iron nuclei shatter into helium nuclei which them shatter into protons and nuetrons. The protons and electrons are forced together forming a nuetron star which is now the size of a city and at a temperature of 50 billion degrees or more. This results in the star being so dense a sugar cube sized piece would weigh trillions of tons on Earth. It's still contracting however, and as it contracts, it rate of spin increases drastically because the planet sized core collapsed down to the size of a city in less than one second. Eventually the mutual repulsion between neutrons stops the core's collapse, and it rebounds back out again. In the meantime, a powerful flood of neutrinos, free neutrons and shockwaves propagate outwards through the doomed stars envelope, blasting it into space. The shockwaves speed outwards at up to 18,000 miles per second, inducing nuclear reactions in the ejecta that rapidly form elements all the way up to uranium and plutonium on the periodic table. Other elements are formed by nuclei rapidly capturing neutrons and becoming heavier elements before they could decay. The new born neutron star starts off as a ball of super-hot nuclear fluid. Eventually a solid crust of heavy elements and nuclear material forms over a solid and liquid interior. They are the densest natural objects in the universe, anything denser would implode at once into the black hole state. Neutron stars can remain visible for millions of years as a pulsar, which emits flashes of radio, visible, x-ray or gamma ray energy at regular intervals so consistently they could be used as clocks. The best known pulsar is the the one at the center of the Crab nebula. It's pulses 30 times a second, matching it's rotation period. The interior of nuetron stars is highly conductive and combined with their extremely rapid spin rate at birth that gives rise to magnetic fields so strong the star can actually experiences "star quakes" and flares that make the Sun's look downright feeble by comparison. The most magenetically active and powerful nuetron stars are refered to as magnetars, whose flares can be detected at intergalactic distances. Over time, their spin rates slow down because their magnetic fields interact with the surrounding interstellar medium, acting like a brake. Eventually, the nuetron star becomes quisiecent and virtually invisible from Earth. Sometimes though the neutron star has a companion star, and when it expands into a red-giant, material spills onto the nuetron star, spinning it up again and reviving it. These are milli-second pulsars, one of which spins 642 times every second.