How could events triggered by a supernova accelerate the death of a main sequence star?

Question

My story revolves around a star going supernova. The 'Earth' in this story is about 100 light-years or more away (a safe distance, but not too far away). I need this supernova to somehow accelerate the death of this 'Earth''s star such that it will slowly become uninhabitable in the next 1 million years.

Answer 1

In Asimov's novel, streams of interstellar matter rich in different elements affect stellar lifetime. Later, learning about catalytic fusion processes, that made sense. Except that the dominant form of power production in a small star like the sun is not the catalytic kind, the amount of material in space is much too small, the interstellar mediumm stays out of the bubble made by the sun, and solar wind blows away from the star.

Something produced in core-collapse supernova moreso than electromagnetic radiation is neutrinos. Gamma ray bursts are beamed not by focusing the light but by channeling the material that then produces the light. So wouldn't neutrinos also be beamed? That's how neutrinos are made in beams in accellerators: the neutrino will be travelling in the same direction as what produced it, when that is greater than the momentum given to the neutrino in its production.

So a burst of neutrinos hits the solar system, causing all sorts of problems but also giving the sun indigestion. A burst of excess power in the dense core will take a long time to work through the layers, and will blow the top of the mantle off when it reaches a shalow enough depth.

Heliosismology tracks the whole process.

Answer 2

They're fine.

Here, I discussed the effects of a supernova on life on Earth. Note that a supernova would have to be within about ten parsecs (~33 light-years) to have harmful effects on life on Earth. Furthermore, the effects would be indirect, destroying the ozone layer (partially or in full) rather than incinerating the planet. At 100 light-years, we're fine.

On to your actual question. The lifetime, $\tau$, of a star on the main sequence is approximately $$\tau=10^{10}\text{ years} \cdot \left[\frac{M}{M_{\odot}} \right]^{-2.5}$$ where $M$ is the mass of the star and $M_{\odot}$ is the mass of the Sun. From this, we can see that a star with more mass will spend less time on the main sequence.

So you need to add mass to the "Sun", and you need to add mass that can be used for nuclear fusion. I can get you specific data for the density of a supernova remnant, which you could use to figure out to amount of material in a given area near the "Sun", but I think it's safe to say that there will not be a significant amount of material useful for fusion anywhere near the "Sun".