[aerohead]

I don't think there's such a thing.
1) the Sun is a main sequence star
2) it's 4.6-billion years old
3) it's lifespan is 10-billion years
4) 3.5-billion years ago, Earth was in the middle of the Goldilocks zone
5) Solar luminosity will increase 10% per billion years
6) By 500,002,015 all multicellular life will be threatened
7) By 1.75-billion years from now, the oceans will have evaporated away
8) as hydrogen fuel is spent and helium is burned, the Sun's interior pressure will overcome gravitational forces, and expand into a Red Dwarf incinerating the solar system