Okay, so I did a bit of research for this one and basically Betelgeuse is too far away to effect Earth when it goes kablooie unless it emits a gamma ray burst (basically a short, dramatic flash of death possibly coming from the star’s poles – a bit like when big things explode in Star Wars, only a million times worse). However Betelgeuse probably isn’t the right kind of star to produce a gamma ray burst; and even if it did, in the star’s current inclination it would miss the Earth.

So yeah, it’s really really unlikely, so stop worrying about it. Seriously, stop worrying.