"WILL THE SUN STOP SHINING ?

The sun is 4.6 billion years old already.Scientists estimate that it will continue to shine bright for about 4.5-5.5 billion years more.The sun will "die"when it runs out of hydrogen and helium.But its death is not as simple as just ceasing to shine.As a matter of fact,scientists believe that the sun will continue to shine even"after its death"

When the sun dies,it starts by collapsing under its own weight.This will produce energy that will actually make it shine much brighter.At the same time,this energy will cause the sun to turn into a red giant.Scientists estimate that the whole process of the sun turning into a red giant will take about five million years.After this,the hydrogen in red giant will take about five million years.

After this,the hydrogen in the sun's outer core will eventually diminish and the sun will collapse again.The remaining elements(helium,carbon,and oxygen) will fuse together,but this reaction will create less energy.

The energy will not be enough to sustain the weight of the sun.So,the core of the sun will eventually shrink into a white dwarf.

And the outer layers will then expand and move outward,creating a planetaria nebula.
As a planetaria nebula,the sun will continue to shine but very giant.

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http://www.universetoday.com/18847/life-of-the-sun/#