== == The temperature of white dwarfs and neutron stars depend on a variety of factors, such as their age and mass. But the short answer is that neutron stars are hotter. Read on for more specific info.
Observed white dwarfs' temperatures have ranged between 150,000 K and 3,900 K. Since white dwarfs generate heat through stored energy, rather than fusion, their temperature decreases over time, theoretically cooling until they become non-radiating black dwarfs. However, since white dwarfs do not have any fusion forces preventing gravity from collapsing their mass, they have a relatively small surface from which to radiate their stored heat so it takes a long time for them to cool. Because of this and the fact that the universe's age is finite, it is thought that no black dwarfs yet exist. At the moment of a neutron star's birth following a type II supernova its temperature will be roughly 10^12 K, but through neutrino emissions, it will cool very quickly. Within seconds its temperature will drop below 10^11 K. At a certain point, predicting the cooling rate of a neutron star is impossible, since we don't have enough data and we aren't sure exactly what makes up the core of a neutron star. Using X-Ray emission detectors, we've been able to estimate the Crab Pulsar's temperature at 2-3 million K. This pulsar is about 1000 years old.
As a point of comparison, the sun's surface temperature is 5,800 K.
For both white dwarfs and neutron stars, accretion of matter will heat them up. Interestingly, they also get smaller because of the additional gravitational force. A white dwarf that is within a binary solar system-- such as HR 8210-- may accrete matter from its companion star, shrinking in size until its hits a critical mass and erupts into a type I supernova, most likely destroying the white dwarf (there's an outside chance that the supernova would leave a neutron star behind, but it's unlikely). Similarly, a neutron star may also accrete matter from a companion star, but rather than triggering a supernova, the added mass will collapse the neutron star until it becomes a black hole.
A low mass star will become a white dwarf star, eventually this will cool to become a black dwarf. A high mass star (at least 8 times the mass of our Sun) will form a neutron star or a black hole, after a supernova event.
Yes, far smaller. A red dwarf is a whole star in and of itself. A white dwarf is the collapsed remnant of the core of a low-to medium mass star. A white dwarf may be about the size of Earth.
No, a white dwarf is not considered a main sequence star. A main sequence star is a star that is still fusing hydrogen in its core. A white dwarf is the remnant of a low to medium mass star in which fusion has stopped.
Such a white dwarf could not exist. Above 1.4 solar masses a white dwarf will collapse to form a neutron star.
It is true that a white dwarf above about 1.4 solar masses cannot exist. When a star dies, most of the mass does not become part of the remnant. A star 5 times the mass of the sun will shed most of its mass during the red giant phase. Only the innermost portion will collapse to form a white dwarf.
white dwarf
white dwarf
white dwarf
A white dwarf is the remnant of a low to medium mass star.
No. A white dwarf is the remnant of a low to medium mass star.
A black hole, a neutron star, or a white dwarf.
A low mass star will become a white dwarf star, eventually this will cool to become a black dwarf. A high mass star (at least 8 times the mass of our Sun) will form a neutron star or a black hole, after a supernova event.
Its Mass.
A white dwarf could not become a red dwarf. A white dwarf is a remnant of a dead star. A red dwarf is a star with a very low mass.
Then, depending on the remaining mass of the star, it will collapse into a white dwarf, a neutron star (aka pulsar), or a black hole.Then, depending on the remaining mass of the star, it will collapse into a white dwarf, a neutron star (aka pulsar), or a black hole.Then, depending on the remaining mass of the star, it will collapse into a white dwarf, a neutron star (aka pulsar), or a black hole.Then, depending on the remaining mass of the star, it will collapse into a white dwarf, a neutron star (aka pulsar), or a black hole.
Sirius B is a white dwarf. So it is low mass compared to other stellar remnants.
Not necessarily. A white dwarf is simply the remains of a low to medium mass star that has died. A red dwarf is a low mass star. Since red dwarfs last longer than medium mass stars, one could easily be older than a white dwarf.