Mike Wiser e-mailed me last night with a stargazing query:

I don’t know what sort of view you have of the night sky at the moment, but if you’d got a good view, take a look at this. Jupiter’s bright at the moment. Tracing straight down from it, I hit the alpha star in Scorpius, which is flickering between red and blue, and seems brighter than I’m used to–though, admittedly, I don’t examine the sky often enough to really qualify even as a amateur in this anymore. I didn’t notice any alerts on spaceweather.com or on the near earth objects lists, so I was curious–can you see something unusual going on here, and if so do you have another resource you suggest I check to find out what’s going on? My brother and father say it’s been that way for a few days now, and that it appears to rotate in the night sky with the other stars, which would tend to argue against a comet…

I didn’t get a chance to look at it, as it was overcast last night. But I did do a little research. The alpha star in Scorpius is called Anatres. It’s normally the sixteenth brightest star in the night sky. Antares is classified as an irregular variable star, which means it has “variations in brightness [which] show no regular periodicity,” but I’m not sure if those variations would be substantial enough to explain the phenomenon Mike is describing.

A few days ago, Missouri State professor Jon Nance wrote in a newspaper column:

Antares’ core is hot enough to burn silicon into iron. But iron has the most stable nucleus of any element and is incapable of fueling any additional exothermic reaction. So a mass of inert iron is growing steadily in Antares’ core. Eventually, it must grow so large as to become incapable of supporting its own weight.

When that happens, Antares’ core will collapse in less than one minute into a black hole in space. A shock wave will propagate outward from that collapse and deposit so much energy in the star’s wispy outer layers that they will, for a few brief days, shine brightly enough to rival all other stars in the Milky Way combined. And then Antares will be gone — forever.

Antares’ end must come within the next million years, but we can’t tell when. Maybe it will be tonight.

What Professor Nance is describing is a supernova. If a supernova happens too close to our solar system, it could damage life on Earth — but according to Science News, a potential Antares supernova would be “too far away to harm Earth.” NASA confirms this: “at 500 light years it is a safe distance from Earth.”

Still, it would be close enough to cause an incredibly spectacular sky show. The last supernova in our galaxy, in 1604, caused a “previously unseen star” to suddenly become “brighter than all other stars” in the night sky — and it was 13,000 light-years away. Antares is 26 times closer than that.

Mind you, I’m not predicting that Antares is about to blow. But it sure would be interesting if it did. (Of course, if Antares is “about to blow,” that would actually mean it was about to blow 500 years ago, and only now is the light from that event reaching us.)