What would happen if Proxima Centauri blew up?
My understanding is that excluding our own sun, the next closest star to the earth is Proxima Centauri at 4.243 light years away. If Proxima Centauri were to blow up, go super nova, do whatever it is that stars do what (if any) would be the effect here on earth? Is 4.243 light years far enough that any effect would be negligible, or would there be noticeable changes to life here on earth?
As I understand it, red dwarf stars can’t blow up.
That being said, if a supernova did occur that close to Earth, it would not be pretty: " Gamma rays are responsible for most of the adverse effects a supernova can have on a living terrestrial planet. In Earth’s case, gamma rays induce a chemical reaction in the upper atmosphere, converting molecular nitrogen into nitrogen oxides, depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation."
Listen here to our very own Bad Astronomer. He states the nearest candidate for “blowupable” is Alpha Virginis (Spica) which is 260 light years away. He also says that about 50 light years is the threshold for danger to earth.
A long ago usenet post about supernovae, and their potential health risks, is here. I lack the math or astronomy chops to look at his info critically, but it seems reasonable.
Short answer, if even a Type I supernova let go, 4.3 ly from Earth (or ~1.3 parsec, since that’s the distance unit he uses in the cite) we’re all going to be hating life.
How long does the x-ray and gamma ray flux from a supernova last? Could you ride it out in, say, the Homestake Mine?
Even if you did, what’s the point? You climb out, every trace of life on the surface of the planet is gone. Unless you create a hell of an “ark” under there, there is no way you can rebuild even a semblance of an ecosystem.
The nearest white dwarf, SFSIK, is Sirius B, Granted, it doesn’t meet the stringent specifications for white dwarf supernovahood. But suppose it did? What might be the effects?
The most horrible thing would happen: In about ten years the filthy Centauri would show up in their space arks and move to Earth sewers and be constantly flying up the loo impinging on our personal freedoms.