How can WD stars live 10 billion years as normal stars and then become white dwarfs for 12 billion years?

Answer 1

No clue what you're talking about.

Answer 2

White dwarf stars are the burned out remnants of normal stars like our sun. In 5 billion years, for example, our own sun will burn up all its hydrogen fuel and become a helium burning star, a red giant. When the helium runs out, the core will collapse into a white dwarf and the outer layers will blow away to form a planetary nebula (it has nothing to do with planets, that's just what it's called). The remaining white dwarf is the size of the earth and the weight of half the sun, so it's very dense. It will continue to burn any residual hydrogen or helium for 100 billion to a trillion years, not just 12 billion, after which time it will become a "black dwarf". There aren't any black dwarfs in the universe yet because it's not old enough.

Answer 3

'Normal' stars, like the sun, only become a white dwarf after they stop burning hydrogen and have finished their red giant phase - not before. WD stars aren't really alive anymore, they are in a stable phase that will just go on forever unless they run into something or something like that. Left alone, they don't change. But they aren't WD until they are 'dead' - before that, the sun is known as a yellow dwarf.

Answer 4

well, white dwarf stars are normal sized stars, like our sun, burned out. after their red giant phase they run out of fuel to burn, and they then turn into a white dwarf, a stable star, but they don't really shine, they are just a ball of matter, so they survive until they hit something.

Answer 5

simple math