[NOTE: Whenever I write about actual cosmic events that might possibly affect us on Earth, I get scared emails from some folks. So let me be up front: there are no stars close enough to Earth to hurt us should they explode. Nothing I write in this post changes that; I'm talking about a star that can go supernova that's closer than I thought any was, but still much too far away to do much to us. So don't panic. But do please enjoy the over-the-topness of what happens when a star explodes. Because it's cool.]
Back in January I started writing what I call BAFacts; daily snippets of astronomy factoids. I post them on Twitter and Google+, and I keep an archive of them on the blog, too. On May 13 I tweeted this one: BAFact: A supernova has to be less than about 75 light years away to hurt us. No star that close can explode, so we're OK. The distance may actually be somewhere between 50 - 100 light years, and it depends on the kind of exploding star, but I have to keep these factoids to about 110 characters to tweet them. Nuance is at a premium.
I got so many replies about that one that I decided to do a theme week, and stick with supernovae. The next day I tweeted this: BAFact: The nearest star that can go supernova is Spica - it’s 260 light years away, so we’re safe, and I linked to a video I did a few years back this. A few minutes later I got a tweet from Nyrath, saying that he thought the nearest star that could explode was IK Pegasi, 150 light years away. I looked this up, and here's the thing: he's right! I had never heard of IK Peg, so I didn't even know it existed. And it turns out it is the nearest star that can explode, though technically it probably isn't. And you know when I say something weirdly oxymoronic like that there must be a good story here, right? Mwuhahahaha. Yes. yes, there is. Stick with me; this is long, but also awesome.
