Doug's Darkworld

Betelgeuse, the 11th brightest star in the night sky, may explode. Wait, what? Yerp, Betelgeuse, the left shoulder of the constellation Orion, is acting very strangely indeed. Over the past few months it has dimmed to less than 40% of its normal brightness, and is now the 24th brightest star in the sky.  The next clear night I’m going to go out and look for myself, Orion is one of the most noticeable constellations in the sky. Never thought it would change in my lifetime. This is, by the way, essentially unprecedented. While there are a few variable stars in the sky including Betelgeuse, never has a super bright star such as Betelgeuse suddenly dimmed this much, at least in recorded history. What the hell is going on here?

Short answer, astronomers don’t know, but it could mean Betelgeuse is about to explode. Betelgeuse is a very unstable and active star, it’s likely just blown a dust cloud or such our way. Still, a supernova? This is because Betelgeuse is a red giant star nearing the end of its red giant phase. And sometimes such stars go supernova. Betelegeuse is maybe 10-20 times the mass of the Sun, and large enough to encompass the orbit of Mars and maybe Jupiter. It’s about 700 light years from Earth, right next door astronomically speaking. Most astronomers think it’s unlikely the dimming means Betelgeuse is going to explode anytime soon, but it is within the realm of possibility. Only eight such explosions have been observed in history, so it’s not like scientists have had much opportunity to study them.

If it does go supernova, it will be quite a sight. Betelgeuse will be the brightest star in the sky, rivalling the Moon in brightness, and so bright as to be visible during the day. And it will last for months. Hopefully the skies here will clear long enough for me to look. Cloudy with sleet today, oh joy. On the plus side, 700 light years away means it probably poses no danger to Earth. We know this mostly because we have a pretty good idea of how common supernovas are, so we can calculate how often Earth has been close to a supernova. Fairly often in cosmic terms, and the planet hasn’t been sterilized yet. Losing the ozone layer would be the biggest danger, the effects would be bad, but life would go on. Phew. We have enough on our plate at the moment.

So two thoughts about this. First, boy, in the pre electric light world this would be a much bigger deal. If one of the stars in Orion had dropped to less than half its brightness in 1800, everyone on Earth would have known about it pretty quickly. And in many eras, it would have been considered an omen or such, the heavens were supposed to be immutable. People wouldn’t have known what to make of it. Pre 1700 or so, before outer space was discovered, people would have been really perplexed. Might have even caused witch burnings or wars. So, good thing it’s happening now, when people don’t believe in superstitious nonsense. Snort. No, the evangelicals who are waiting for Jesus to come back see this as another sign of the End Times. Stay tuned.

Which leads to my second thought, a somewhat eccentric thought trail. This Betelgeuse dimming event is the fourth odd and unprecedented event in the sky since Tabby’s Star dimming in 2015 suggested (albeit unlikely) alien megastructures. The second being Oumuamua and Comet Borisov. Tabby’s Star suggesting aliens, the next two being the first two confirmed interstellar visitors to the Solar System. And now an interstellar event visible to the naked eye, that rarely happens. One might even include the recently discovered repeating FRB, though that’s a stretch.

Connecting these events is no doubt pareidolia on my part. Seeing patterns where none exist. Thinking aliens might announce their presence by making changes in the sky isn’t an original idea. In fact the whole “the aliens are coming” trope seems pretty clearly to be the modern version of “Jesus is coming.”  Still, if the aliens suddenly arrive, I will become a famous blogger. The guy who saw the signs that the aliens were coming! The Nostradamus of our time! Fame and fortune would surely follow. And what a nightmare that would be. Fortunately it’s about as likely as Betelgeuse going supernova in our time.

On a more serious aliens vein, a case has been made to mainstream SETI (The search for extraterrestrial intelligence.) There are excellent reasons for doing so, both SETI and astronomy in general will benefit. The reason SETI has been left out in the cold is because it’s easy for science deniers and evangelicals to ridicule. Humans just love to shoot themselves in the face, we’re an odd species for sure.

I’m sorry this post is a day late, still helping a friend convalesce from an operation. She flies home soon though, and I will resume posting on a more regular basis. Take that as a threat or a promise I suppose. Have a great week everyone!

Copyright © 2020 Doug Stych. All rights reserved.

(Image: Remnant of Cassiopeia Supernova of 1572. Credit: Pixabay, free for commercial use, no attribution required.)