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Supernova May Wipe Out Earth... Someday
Halster writes "And it could take our planet with it. Reported in the New Scientist. Harvard student Karin Sandstrom discovered the star while researching a paper. It's named HR 8210, and is a white dwarf about 150 light years from our planet, that's 10 light years short of the 160 to 200 theoretical light years thought to be a safe distance from a SuperNova. Left alone it won't turn SuperNova, but it's parked next to another Sun that will "Very soon" turn into a red giant star and expand lending mass to the HR 8210 which will then push HR 8210 over the edge and go SuperNova on us. Course "Very soon" to an astronomer is hundreds of millions of years. And by that time the two stars will likely have moved away from the earth. So don't jump into your escape pod yet." Update: 05/23 20:16 GMT by M : Heh. It seems New Scientist didn't get the story quite right. :) Read the correction below.
I'm not a rocket scientist, but one would think that if we dont actually go outside we would be unaffected by the lack of an ozone layer.
Or if we do need to go outside, we would be unaffected if we wore protective clothing.
If this really happened to us, I can see the vast majority of wildlife being bombarded by radiation.
But what if we grew all our plants in greenhouses with high-tech sun filters, or even grow them indoors under artificial lighting?
Then we could feed them to cows, chicken, etc.
We could very well extend the subway system and travel exclusively underground, board up all the windows (grin), and coat our buildings with some sort of shielding.
It would be hard to do this for absolutely everyone, but hey even if it blew up today it would take over a century for anything to get here.We have millions of years. Should we really worry?
Astronomer (giving a lecture in a planetarium): "And in about 2 billion years, the sun will exhaust its fuel supply and explode, consuming the earth and all the planets."
Woman in audience: "Excuse me, did you say 2 billion years?"
Astronomer: "Yes, 2 billion years."
Woman: "Oh, what a relief! For a moment I thought you said '2 million years.'"
If the thing is 150 l-yrs away from us, that means everything we see about it is 150 years late, right ? So if it ever does explode, by the time we see it coming it will be too late already. Even if we were to launch some sort of defensive weapon or shield or whatnot, it would inevitably miss the target because it would be another 150 years late. Think long-distance phone lag, measured in years, not seconds.
-Billco, Fnarg.com
So many Christians so few lions...
Only 'flamers' flame!
As i remember from astronomy course, supernova is exploding star. Speed of that explosion frontier is near speed of light... Acvtually, it should be nuclear chain reaction, as stars are powered by nuclear power.
And that means you can't kill explosion of supernova with nuclear weapons, and you can't make a shield strong enought as earth will be vaporized...
* Origin: XBase BBS (2:490/4100) Well the good old days may not return and rocks might melt and sea may burn.
Supernova May Wipe Out Earth... Someday
And it could take our planet with it.
Err... am I missing some key distinction here? Last I checked, "Earth" and "our planet" were one and the same.
you probably can't make a shield, but something that far away wouldn't vaporize the Earth. Supernovas are going on all the time and they don't vaporize you unless you're within a certain distance, which I don't know what is, but a lot closer than 150 light years.
Hi,
I'm Karin, the one quoted in this article as having discovered the supernova progenitor. I just wanted to let you all know to pay very little attention to the article. The reporter has taken one fact: that this might be a good candidate for a Type Ia supernova, and constructed a big mess out of it. I am very embarassed by this so I just wanted to clear up a few things.
First, I did NOTHING in the discovery process. I was just writing my senior thesis on white dwarfs and happened to study this system. It was discovered in 1993 by two separate groups of scientists (Landsman et al 1993, and Wonnacott et al 1993) They found the mass to be 1.15 solar masses, which is relatively large for a white dwarf star, but not the "just shy" of the Chandrasekhar limit that the reporter says. It is 0.3 times the mass of the sun shy of the limit, and that is a lot of mass. Lots and lots of people have studied this system since then, and many have commented on its possibilities for a supernova. All that I did in this story is to mention the system to a scientist here at Harvard who happens to simulate the evolution of a binary system towards a supernova and then mention in in a public talk about my thesis when a New Scientist reporter happened to be in the audience. The reporter got very excited and wrote this article, and left out the actual work that is being done on the evolutionary scenarios to sensationalize the possibility of a near earth supernova.
Second, what we have found, if anything, is that by the time that the white dwarf star has accreted enough mass from its companion to exceed the Chandrasekhar limit of 1.4 solar masses, it will be at least 10 kiloparsecs from earth, which is well on its way to the other side of the galaxy. The star will not pose any threat at all to earth. This is also hundreds of millions to billions of years in the future.
I think the interesting part of this story is the terrible state of scientific news reporting in some popular journals. We discussed these problems extensively with the reporter and they were completely disregarded in the final version. Be on the lookout for our letter to the editor if you are interested.
If anyone would like to know more about this, I'd be happy to explain what we really think is going on...unless you are a reporter, in which case don't bother...I'm done with them.
Thanks,
Karin Sandstrom
Someone's watched Armageddon one too many times... BTW. it WOULDN'T vaporize the earth.... A supernova 150 ly away would probably disrupt global weather patterns, as well as probably damaging, destroying the ozone layer.. Perhaps a bit of research is due before proclaiming earths impending doom
Here's some quick calculations that might put some things in perspective:
1. Volume of the galaxy, assuming a disc 50,000 ly in radius and 2000 ly in thickness is about 8e12 cubic ly.
2. Volume of space within 200 ly of Earth is about 3e7 cubic ly.
3. Assuming the distribution of supernova events is fairly even throughout the galactic disc, that means one out of every 300,000 supernova events is within 200 ly of Earth.
4. Based on an estimated frequency of once every 100 years, a supernova should occur within 200 ly of Earth on average once every 30 million years.
Now, I'm ignoring the galactic halo, which has a low stellar density, and the fact that supernovae will tend to be more common towards the center of the galaxy, but that shouldn't change this estimation by more than an order of magnitude. If my calculations are correct, then this means that Earth must have been near supernovae several times in the past 4.5 billion years. Therefore, if all this is true, then life on Earth must be pretty resilient if we're here talking about it today.
X-rays, gamma rays, microwaves, and plain old-fashioned heat all travel at the speed of light. This star, as has already been established, poses zero threat to earth. But if it did, we'd see the light from the supernova the same time the x-rays were frying us. We'd be dead, probably, before the actual matter from the star reached us.
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