You're confusing the universe with our solar system. The Sun is expected to have a lifespan of approx. 10 billion years, of which 4.6 billion have already elaps

You're confusing the universe with our solar system. The Sun is expected to have a lifespan of approx. 10 billion years, of which 4.6 billion have already elapsed. As for the universe, see various conjectures at https://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe https://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe