After hydrogen fusion in its core has diminished to the point at which it is no longer in hydrostatic equilibrium, the core of the Sun will experience a marked increase in density and temperature while its outer layers expand to eventually become a red giant.
It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus, and render Earth uninhabitable, eventually engulfing it too.
Surreal. This is great! I can just imagine circling the sun in some sort of space craft. A solar flare juts out of the surface of the sun. Another one appears and you know it's time that the space craft is about to enter the sun's gravitational field. The track sounds like it gives wonder and doom at the same time.