The spiral structure around the old, giant star R Sculptoris is due to winds blowing off outer. The big question that should be on your mind is, with these two competing processes going head-to-head, which one will win for each planet? The most straightforward calculation would be to compute mass loss rates, orbital outspiral rates, and solar radius as a function of time, and see what happens. The Earth in particular, presently ~150 million kilometers from the Sun on average, will see its orbital distance increase in proportion to the Sun's mass loss.īut the Sun also increases in size, and if it creates too much drag on an orbiting planet, that planet will spiral into the Sun itself. As the central gravitational object in our Solar System decreases in mass, the planets tend to spiral outward, as they're more loosely gravitationally held.

As the Sun swells into a red giant, its outer layers become more tenuously held, and will get blown off, out of the Solar System entirely, causing the Sun to lose mass. This is the base model for how our Solar System will evolve over time. A monstrous supergiant like Antares or Betelgeuse will be forever beyond our Sun's reach, as we will never begin fusing carbon in the core: the necessary step for growth to this size.

giant phase, some 250 times its current size. The Sun, today, is very small compared to giants, but will grow to the size of Arcturus in its red.

Red giant particular