Betelgeuse, normally one of the brightest stars in the sky, has been steadily dimming over the past two months, to the point it’s no longer in the top ten for magnitude.
Betelgeuse is a red super-giant, and there’s speculation that the sudden dimming could be a sign IT’S GONNA BLOW! If it does, it would be the first supernova in our galaxy since Kepler’s time, early in the 17th century.
Likely could be visible by daylight, or as bright as the moon at night.
Or it could all just be a hiccup and nothing will happen for 800,000 years.
Since information can only travel at the speed of light and Betelgeuse is believed to be 640 light years away whatever we’re seeing now happened 640 years ago.
So it if pops off in reality that happened 640 years ago and we’re just seeing it now.
If there’s a beam, it’ll be along the axis of rotation. We know we’re not along Betelgeuse’s axis of rotation, because it gets starspots (similar to sunspots), which cause small but detectable changes in brightness as they rotate on and off the portion of the surface that face us. We wouldn’t see that if the axis is pointed towards us, because if it did, we’d always see the same hemisphere.
And yes, there’s a good chance that even if we don’t see it blow imminently, we might see it blow sometime in the next 640 years. Which in turn means that there’s a good chance that it has in fact already blown. It’s one of the very few, possibly the only, naked-eye star for which that’s true.
After the particle storm sweeps away 90% of Terrestrial life, any surviving human culture will worship The Burning God whose laser projector cools at His shoulder. Believers will offer themselves for ritual immolation. Water will be damned. The Burning God wants us hot! Burn, baby, burn!
Would it be better to see it right away, though? Will there be a sudden burst at the beginning, or gradually getting brighter and then gradually dimming?
When astronomers say a Supernova is ‘imminent’’ they are talking about timescales measured in thousands to hundreds of thousands of years. It could go off today, or 10,000 years from now.
Or 1,000,000. Most of what we know about Betelgeuse is approximate. It could be 640 light years away, but that’s plus or minus a few hundred light years. We do not know its size for sure - it is certainly a red giant and will go supernova some day, but the time frame for that is dependent upon its size, and our guesses on that have a pretty wide margin of error, too. Its size determines its lifespan, and if you don’t really know the former you don’t know the latter. It could have already gone poof and we’ll see it by Easter, or it might not go poof for a length of time beyond human imagination.
Of course, I sure hope it goes now, because it would be a sight unlike anything else - brighter than the Moon, visible during the day, something unlike any celestial object most humans have, or will ever get, to see.
