How long does a normal star exist before it gets to be a white dwarf star?

Answer 1

It depends on the mass of the star and, to a lesser extent, on its initial composition.

The time a normal star exists before it gets to be a white dwarf star is, approximately,

T = 1E+10 years (M/Msun)^(-5/2)

Our sun will be 10 Billion years old when it leaves the main sequence. A star that is 10 times more massive than our sun will exist only 32 Million years on the main sequence.

Answer 2

Well, it depends on the size of the star.

By a 'normal star' you probably mean what we call 'Main Sequence' star. And it varies a lot. A star's life is determined by the ammount of fuel it has. For a star like our star, the Sun or Sol, it's around 9 or 10 billion years, which can be more or less depending on it's size.

Stars fuel is hydrogen. They fuse to form helium atoms, which can also be fused but only at migh higher tempatures, which requires greater mass. And, Helium combines to form heavier elements up to around Nickle and Iron. These reactions happen sucessively. Firs the star burns out the Hydrogen, then the resulting Helium and so on until it isn't large and hot enough to fuse whatever's left, and then the core colapses. But it's important to note that larger stars will burn lighter elements faster than smaller stars.

Ours is a relatively small star, too small to ever start Helium fusion. So.. not only do stars live for a long time before becoming white dwarfs, they can also live a lot longer than ours will.

Answer 3

There really isn't such a thing as a normal star. But if you mean a star like our sun, they live about 10 billion years until they start to expand into a red giant.
That can last for a few million years while the star continues helium burning in its core.
Eventually, there isn't enough heat produced by the core to support the outer mass and it collapses, creating a nova and blowing off a lot of mass. What's left becomes a white dwarf (this last phase is only a few weeks/months long).

Answer 4

That depends on the mass of the star. The Sun is about 5 billion years old and has another 5 billion years to live; more massive stars burn their fuel more quickly, while lighter ones can last up to a trillion years.

Answer 5

It takes about 9 million from the beggining of a stars existence. our sun will be their in 4 million years.

Answer 6

A really long time.