For one of the brightest stars in the sky, Betelgeuse still has some surprises up its sleeve. We’ve known for a couple of years it’s surrounded by a cloud of gas, but new observations show that nebula is far larger than previously thought!
[Click to enorionate.]
This new image is care of the Very Large Telescope, and shows a very deep and very high-resolution shot of Betelgeuse in the infrared. The inner black circle is the 2009 shot of the star and its surrounding gas — what we knew about before — and the big image shows all the gas around it just discovered. At the very center is a red circle indicating the actual size of Betelgeuse on this scale — it’s a red supergiant, and nearly two billion kilometers in diameter.
This structure is actually a wind of material blown off of the star itself. The exact mechanism behind this is unclear, though. Red supergiants are so big that gravity on their "surface" (they don’t really have a surface; they just kinda fade away into space) is very weak, and they can barely hold on to the material there. They are also incredibly luminous — Betelgeuse is 6000 trillion kilometers away, yet one of the brightest stars in the sky — so much so that the pressure of light is very strong. This pressure can lift material off the surface and blow it into space. It’s also known that Betelgeuse has gigantic convection cells bringing hot material from deep below up to the surface, and that’s part of this process as well.
Once the material is ejected it forms into dust grains: complex molecules including hydrocarbons. The astronomers doing this observation detected oxygen-rich dust in this nebula (PDF), which given the environment is most likely silica or alumina. Silica, also known as silicon dioxide, is the main constituent of sand and quartz! That’s the most common constituent in the Earth’s crust — over 60% by mass — and we think that a lot of the materials in the Earth’s crust actually formed in the winds of red giants and supergiants.
Think about that the next time you’re playing at a beach this summer. Billions of years ago, some now long-dead red star belched silicon dioxide into space, seeding a nearby nebula with materials… and this cloud collapsed to form our Sun and planets, with some of that interstellar silicon dioxide making up the sand under your feet.
Not to mention that a lot of that water you see in the ocean came from giant comets slamming into the Earth shortly after it formed. Does that make your heart pound, your blood race? Because the iron in your hemoglobin came from massive stars that exploded long ago. If that makes you smile, why, the calcium in your teeth most likely came from an entirely different kind of star that exploded eons ago as well.
We’re directly tied to stars like Betelgeuse.
And oh: while you’re at the beach, do me one more favor. Find a grain of sand, just a single grain about a millimeter on a side. Now give it to a friend, placing it on their outstretched finger. Walk about 40 meters away, turn around, and look at your friend. The grain of sand will be invisible to your eye, far too small to see. Yet at that distance, that grain of sand appears to be the same size as the entire image above of Betelgeuse.
And you thought you were just going to the beach.
Someday, Betelgeuse too will explode as a supernova. It will briefly become as bright as the Moon, then fade over months. The material we see here will get slammed by octillions of tons of gas moving outward 10,000 times faster than a rifle bullet, destroying it. And when it’s all done, our familiar constellation of Orion will be left without his right shoulder.
But it’s worth it. What planets will coaleasce, what suns will shine, what forms of life will one day arise from that material, and wonder which star it was to which they owe their existence?
Image credit: ESO/P. Kervella
The newest edition of the SETI radio show "Are We Alone" is up, and in the segment called Skeptic Check astronomer Seth Shostak and I poke fun at the latest silliness about Betelgeuse and the Mayan doomsday. The rest of the show is, as usual, really good and fun to listen to (all about ESP — but you knew that already), so head over there and give it a download. But do it before December 21, 2012.
Or wait until afterwards. It’ll still be around, as will the Earth.
It’s been a couple of days since the foofooraw involving Betelegeuse, 2012, and media laziness took place. As you may recall, a site in Australia made some dubious connections between 2012 and the red supergiant star Betelgeuse exploding, which you may imagine I took a fairly dim view on. As bad as that was, it got worse when The Huffington Post weighed in, adding their own nonsense to the story, misattributing parts of the story and making even more faulty connections to 2012.
The story went viral rapidly. Other media venues quickly picked up on it, furthering the nonsense without doing any independent investigation of it. Happily, not everyone got it wrong; I’ll note that the first venue that apparently got it right was Fox News, who linked to an earlier article I wrote about Betelgeuse.
I was also contacted by Jesse Emspak from International Business Times, who asked me specific questions about it and wrote a very well-written and factually accurate article about all this, doing something that made my heart sing: not just presenting the real science we could get out of a Betelgeuse supernova, but making that the focus of the article! As it should be. Kudos to him and IBT.
Stories like 2012 and nearby supernovae are sexy, easy to sell, and get eyeballs on a webpage. It’s the devil’s bargain to write about them even on a skeptical astronomy blog; it can reinforce bad science in people’s minds, or it might put a spotlight on something that could otherwise wither and die on its own (which is why I didn’t write about this story until HuffPo posted it). It’s also amazing to me how some media — some actual, mainstream news sources — didn’t do any real fact-checking before putting up links to HuffPo. It once again reinforces what I learned long ago: keep a very skeptical frame of mind when reading or listening to the news. If they can mess up something as simple as this, then what else are they getting wrong?
I swear, I need to trust my instincts. As soon as I saw the article on the news.com.au site desperately trying to link Betelgeuse going supernova with the nonsense about the Mayans and 2012, my gut reaction was to write about it.
But no, I figured a minute later, this story would blow over. So to speak.
I should’ve known: instead of going away, it gets picked up by that bastion of antiscience, The Huffington Post.
The actual science in the original article is pretty good; they talked with scientist Brad Carter who discusses the scenario of Betelgeuse going supernova. The whole story is pretty interesting — I wrote about it in detail the last time there was nonsense about Betelgeuse blowing up — but in a nutshell Betelgeuse is a red supergiant star in Orion with about 20 times the mass of the Sun, and it’s very near the end of its life. When stars this massive die, they explode as supernovae. The distance to Betelgeuse is unclear (it has a very puffy outer atmosphere which makes distance determination somewhat dicey) but it’s something like a bit more than 600 light years, way way too far away to hurt us.
It’s the question of when that the two articles go off the rails. Betelgeuse may explode tomorrow night, or it may not go kerblooie until the year 100,000 A.D. We don’t know. But given that huge range, the odds of it blowing up next year are pretty slim. And clearly, the original article was really trying to tie in the 2012 date to this, even when it has nothing to do with anything. The tie-in was a rickety link to scuttlebutt on the web about it, but that’s about it.
What’s worse, the HuffPo article attributes the date to Dr. Carter himself, but in the original article he never says anything about it; the connection is all made by the article author. Given how popular HuffPo is, I imagine a lot of people will now think an actual scientist is saying Betelgeuse will blow up in 2012.
OK then, tell you what: I’m an actual scientist, and I would give the odds of Betelgeuse going supernova in 2012 at all — let alone close to December, the supposed doomsdate — as many thousands to one against. It’s not impossible, it’s just really really really really really really really unlikely.
BABloggee Alereon (and many others) sent me to an interesting site: Life After the Oil Crash Forum — a forum that apparently has a lot of doomsday-type scuttlebutt posted to it.
An anonymous poster there says he has heard that the star Betelgeuse is about to go supernova, maybe as soon as a few weeks:
I was talking to my son last week (he works on Mauna Kea), and he mentioned some new observations (that will no doubt get published eventually) of “Beetlejuice”; it’s no longer round. This is a huge star, and when it goes, it will be at least as bright as that 1054 supernova…except that this one is 520 light years away, not 6,300 [...]
When it collapses, it will be at least as bright as the full moon, and maybe as bright as the sun. For six weeks. So the really lucky folks (for whom Betelgeuse is only visible at night) will get 24 hour days, everybody else will get at least some time with two suns in the sky. The extra hour of light from daylight savings time won’t burn the crops, but this might. Probably, all we’ll get is visible light (not gamma rays or X-rays), so it shouldn’t be an ELE. It’s sure gonna freak everyone out, though…..
Then it will form a black hole, but we’re too far away for that to matter.
The buzz is that this is weeks/months away, not the “any time in the next thousand years” that’s in all the books.
The basic takeaway:
OK, folks, first: when news like this comes from an unnamed source on some random forum, and that source is not even a primary one, and that secondary source quoted is also unnamed, and that person heard it from a third party that is also unnamed… well, oddly enough my skeptic alarm bell in my head rings loudly enough that my eardrums explode outward in every direction at the speed of light.
I hope I’m being clear here.
The first important thing to note here is that if Betelgeuse explodes, we’re in no danger at all. It’s too far away to hurt us. Got that? It’s the most important thing to remember here, because I’m quite sure this story will get wildly exaggerated as it gets repeated.
So, what’s the deal with Betelgeuse? What is it, will it explode, and if so, when?