Neutron Stars

The average density of a neutron star with the same mass as the sun would be about 1 x 10^17 kg/m^3. Neutron stars are incredibly dense objects, as they are formed from the remnants of massive stars that have undergone supernova explosions.

White dwarfs are prevented from collapsing further by electron degeneracy pressure. If the mass of a stellar remnant exceeds the Chandrasekhar limit, about 1.4 solar masses, gravity will overcome this pressure and form a much smaller and denser neutron star. Further collapse in a neutron star is prevented by neutron degeneracy pressure up until the Tolman-Oppenheimer-Volkoff limit of about 3 solar masses, at which point gravity causes a complete collapse, forming a black hole.

Of course you can, that is how we know they exist.

However you will need a telescope designed to look in the x-ray range of the electromagnetic spectrum, since neutron stars do not emit much of their energy in the visible range.

The mass of a typical neutron star is believed to be between one and three times the mass of the sun. However, in size they would be much smaller than the earth, something on the order of around ten kilometers in diameter.

Supernova explosions are responsible for producing elements with atomic masses greater than iron through nucleosynthesis processes. During these violent events, heavy elements are forged from lighter elements through rapid fusion reactions.

No, black holes cannot turn into neutron stars. Neutron stars form from the remnants of supernova explosions of massive stars, while black holes are formed from the gravitational collapse of massive stars. Once a black hole is formed, it will remain a black hole and will not transform into a neutron star.

An accretion disk around a neutron star is composed of gas and plasma spiraling into the dense neutron star due to its strong magnetic field and intense gravitational pull, leading to high-energy emissions. In contrast, an accretion disk around a white dwarf is typically composed of lighter elements like hydrogen and helium, with the white dwarf's lower mass resulting in lower energy emissions.

When a collapsed core becomes so dense, it reaches a state known as neutron degeneracy, where neutrons can exist in close proximity due to the exclusion principle preventing them from occupying the same quantum states. This forms a neutron star, where the core is primarily composed of densely packed neutrons.

Galaxies contain varying numbers of star systems, star clusters and types of interstellar clouds. In between these objects is a sparse interstellar medium of gas, dust, and cosmic rays. The bulge is actually the outline of a black hole's ergosphere, wherein such matter is being gravitationally attracted.

It should also be noted that galaxies are actively evolving; i.e. providing for the birth of new stars, star systems, and star clusters. This process is more apparent in the areas of gravitational disruptions, like a galaxy's central black hole. Consequently, the sparse interstellar medium of gas and dust can form stars in the ergosphere area of a black hole due to the intense gravitational pressure and drag.

Among the smallest astronomical objects is the neutron star, which is smaller than Earth's Moon, but larger than some. Next would be our Moon, followed by the shrunken White dwarf. Normal stars would then follow, and a galaxy is the largest , being a collection of millions or billions of stars.

Neutron Star : as small as 20-24 km

Moons : for Earth, 3400 km in diameter

White Dwarf star : from about 5000 to 50000 km diameter

Galaxies : 2000 to 100000 light-years across

Neutron stars are born from massive stars collapsing, which conserves the original star's angular momentum. Since the original star had a slow rotation, the neutron star that forms from it will have a faster spin due to the conservation of angular momentum.

Depends on the age of the neutron star. As a neutron star no longer has any method to produce heat, it will slowly cool over time.

A young neutron star will have a core temperature of about 106 kelvin.

The most immense gravity for it's size of any single object in the universe. If it had been a slightly larger star before it went supernova and wound up as a neutron star, it would have collapsed into a black hole - where not even light could escape it's gravity.

All "pulsars" are neutron stars - it's just "we" term pulsars as neutron stars who's orientation towards us shows the beam of electromagnetic radiation.

Other neutron stars who's orientation, do not point towards us are not called pulsars, although they exhibit the same characteristics.

No, not all neutron stars are pulsars. Pulsars are neutron stars that emit beams of radiation that are detectable from Earth as rapid pulses of light. While many neutron stars are pulsars, not all neutron stars exhibit this pulsing behavior.

Neither.

Our Sun will turn into a red giant, and then cool to become a white dwarf.

In all likelihood you wouldn't be around to read the answer. Magnetars produce an amazing amount of X and gamma rays, that our Earths atmosphere wouldn't be able to deflect. So we would all be dead.

There are no neutron stars with 5 solar masses because one if a neutron star exceeds 3 solar masses, the neutrons inside would no longer be able to support the extreme gravity, so the neutron star would then collapse into a black hole.
A neutron star is prevented from further collapse by a force call neutron degeneracy pressure. Above 3 solar masses gravity will overcome this force and the stellar remnant will collapse completely to form a black hole.

After a high-mass star explodes as supernova and leaves a core behind, the core would become a neutron star or a black hole. If the core is less than 3 solar masses, it would become a neutron star; if the mass exceeds 3 solar masses, the core would continue to collapse, forming a black hole.

Most stars spin (albeit is very slowly), but when the star starts to shrink it will speed up due to conservation of angular momentum. Moreover because a neutron star is so very heavy it takes a long time for it to slow down (breaking can occur via magnetic fields for example).

You can test this principle yourself by sitting into an office chair, spreading your arms, and have someone give you a good whirl. You will find that while spinning you will spin faster if you pull your arms inwards and slower if you put them out again.

Neutron stars rotate rapidly due to their conservation of angular momentum. When a massive star collapses into a neutron star, its core spins faster as it contracts. Since angular momentum is conserved, the neutron star continues to rotate rapidly as a remnant of the collapsed star.

A neutron star is already a dead star it can produce no more energy, although massively dense it will just continue to radiate its energy out into space until there is nothing left. There is an alternative ending for a Neutron Star and that is, if it was a part of a binary system or had enough mass collect on it could collapse further to create a Black Hole.

The crust of a neutron star is primarily composed of heavy elements like iron and nickel. As the star cools, these elements solidify into a solid lattice structure. Additionally, the crust may also contain other materials like silicon and magnesium.

There is an upper limit to the mass of neutron stars because if the mass exceeds a certain value, known as the Tolman–Oppenheimer–Volkoff limit, the gravitational force would overcome the pressure from neutron degeneracy and cause the star to collapse further into a black hole. This limit is estimated to be around 2-3 times the mass of the Sun.

The neutron star emitting radio waves and visible light is likely a pulsar. Pulsars are highly magnetized, rotating neutron stars that emit beams of electromagnetic radiation from their magnetic poles. As the pulsar rotates, these beams sweep across our line of sight, causing periodic flashes of light and radio waves to be observed from Earth.