What exactly is a White Dwarf? And can it become a Nova or Super Nova?

Answer 1

Some pretty good answers. A white dwarf is the hot, non-fusing "ash" core left after stars below a certain size leave the main sequence hydrogen burning phase, finish their red giant phase, and cast off their outer atmospheres in a planetary nebula. White dwarfs can also blow up as (type Ia) supernova, if they have a close companion star from which they can suck hydrogen thru the inner Lagrangian point. If enough material is brought in so the mass of the dwarf reaches the Chandrasekhar limit of about 1.4 Ms, gravity overwhelms electronic repulsion and the star collapses, setting off carbon fusion which destroys the star. The sharp limits on the physical conditions for the explosion make them useful as "strandard candles" for cosmological research.

When incoming material stacks up and periodically ignites in hydrogen burning on the surface of the dwarf, we see the resulting smaller explosions as nova.

Larger stars end in type II supernova, forming either neutron stars or black holes. Type 1 supernova leave nothing.

Answer 2

A white dwarf is a very old star that is left over after a nova or supernova reaction. If the mass of the star is not above Chandrasekhar's Limit (larger than our sun) it cannot form a black hole. If it is below a certain critical mass, it cannot even form a neutron star. So a white dwarf is a very small star that is left over after a larger star dies. It is mostly helium and will eventually (after a long, long, long time) burn out as a black dwarf.

Answer 3

A white dwarf is what is left after a star has exhausted most of its fuel, after ejecting its outer shell in a planetary nebula.

It cannot become brighter on its own, However, if the white dwarf is part of a multilpe satr system, and the other star gets too close -- within its Chandrasekhar limit -- some of the matter of the other star will spill on the white dwarf, and accumulates until it blows up, that is a type 1 supernova.

Answer 4

Those stars, which have less mass than 1.5 times more than Sun, are not massive enough gravitational force takes over the heat of star. so these stars, wouldn't become a Neutron star or black hole. In fact, when they are burning their hydrogen, they become a huge,red star, called Red Giant. then they explode and throw the rest of hydrogen in outer space. therefor they become cooler and begin to shrink. but the pressure of shrinkage cause the helium and other molecules join together and make more massive atoms. so they begin to release energy again and that prevent from getting smaller and make a black hole or other things. and we call then With Dwarf. but finally they would use all the atoms. and they can't create more massive molecules. so they would turn off. and they called Brown Dwarf in this level.

Answer 5

a white dwarf is a phase of a star when it dies.
after the white dwarf loses its fuel it turns to a red giant, then cools to a white dwarf. if it is more than 1.4 times the mass of the sun, it collapses to a neutron star. Carbon-oxygen white dwarfs undergo a nuclear fusion reaction leading to a supernova.

Answer 6

white dwarf is a small star near the end of it's life being overcome by gravity. it cannot become a nova or supernova unless it is over i forget the name but like ~1.46 times as massive as our sun :]

Answer 7

A white dwarf is a star that's almost burnt out.

Answer 8

Our Sun, when it dies, it will become a "White Dwarf" instead of the "Black Hole" because it does not have sufficient mass.

Answer 9

Yes