Betelgeuse, Betelgeuse, Betelgeuse!

A very cold person points out Betelgeuse

Betelgeuse is a massive star at the very end of its life and could explode any second now!  Every time I hear that I get really really excited.  Like a kid in a candy store that's about to see a star blow up like nobody's business.  This giddiness will last for a solid minute before I realize that "any second now" is taken on astronomical timescales and roughly translates to "sometime in the next million years maybe possibly."  Then I feel sad.

But you know what always cheers me up?  Calculating things!  Hooray!  So let's take a look at the ways Betelgeuse could end its life (even if it's not going to happen tomorrow) and how these would affect Earth.