Question: How old do you think the sun will live if it is allready 4 billion years old?

Amy Tyndall answered on 10 Mar 2013:

We think our Sun will be an incredible 10 billion years old before it forms a planetary nebula! So it has a little while to go yet. Although it won’t stay looking the way it does now for this whole time – before it becomes a PN, it will initially get bigger (hundreds of times the size the Sun is now) to become a Red Giant,

Here’s a little picture for size comparison!