sun go boom
July 17, 2006 12:02 PM   Subscribe

Life (Briefly) Near a Supernova (pdf, Google cache) by Steven Dutch (UW-Green Bay). What might it be like on a planet orbiting a star that went supernova? "It would take on the order of 100,000 seconds, or about a day, to receive enough energy to vaporize the Earth." Yes, Arthur C. Clarke and Larry Niven are name-checked. (And yes, the Sun is too small to actually go supernova, killjoy.) Via the nonist.
posted by languagehat (19 comments total) 1 user marked this as a favorite
*dons tinfoil hat anyway*

*awaits apocalypse*
posted by mrmojoflying at 12:12 PM on July 17, 2006

Interesting and esoteric: exactly the kind of thing that deserves to be posted here. Cheers.
posted by rhymer at 12:20 PM on July 17, 2006

Brilliant! Thank you, lh.
posted by Baby_Balrog at 12:28 PM on July 17, 2006

Actually we could be screwed by another star.
posted by rhymer at 12:29 PM on July 17, 2006

Homework: How hot would the Earth get if a star went supernova that was 100 light years away?
posted by vacapinta at 12:41 PM on July 17, 2006

Very fun reading. Thanks.
posted by teece at 12:44 PM on July 17, 2006

Great link, languagehat! But it's quite a thing to think about more heat on this particular summer day in the city! (Back of neck dirt 'n gritty? Check.)

At least annihilation via a gamma ray burst doesn't seem too likely these days.
posted by Songdog at 1:22 PM on July 17, 2006

Yes, a good read. I especially liked the calculation that the light reflected onto Earth's nightside from interplanetary dust would be brighter than ordinary daylight. Definitely a wow.
posted by String at 2:11 PM on July 17, 2006

[this is super awesome]
posted by Optimus Chyme at 2:51 PM on July 17, 2006

Sometimes stuff like this makes me wish I would have liked math more.

Cool stuff; I like visualizing an Earth that boils away.
posted by craven_morhead at 2:52 PM on July 17, 2006

Rhymer's link is interesting because the star is so close 150 light years). But if it goes off, it will be at the bare minimum size (something like 3 solar masses) where it's possible for it to become a supernova. And as the article itself says, it could be hundreds of millions of years before that happens.

There's another kind of star which is interesting: really huge stars which live fast, die young, and go out with a really big bang. The best example of that is Eta Carinae. It's about 7500 light years away, but when it comes to a star like that one, that's not necessarily a safe distance.

Estimates place it at between 100 and 150 solar masses, and when stars that large detonate they become what astronomers refer to as "hypernovas", which make supernovas look like wet firecrackers. No one knows when Eta Carinae will go off, but it will probably be sometime in the next few ten thousand years. It's entirely possible it's already happened. (Given the amazing changes in brightness observed over the last 300 years, it seems likely that something rather drastic is happening to that star.)

We're off-axis for a gamma-ray beam from it, but with something that big that may not save us.
posted by Steven C. Den Beste at 4:17 PM on July 17, 2006 [1 favorite]

I have a hell of a time with the science of astronomy. The intellectual side of my mind is endlessly fascinated by the mechanics of the universe, but if I spend more than five or ten minutes thinking about it, I find myself getting physically nervous and wound up - I think it's sort of the opposite of claustrophobia - thinking about things of that scale, and imagining the miniscule nature of our world compared to the vastness of space.
posted by stenseng at 5:09 PM on July 17, 2006 [1 favorite]

Thanks, I've got my bed-time reading for tonight. :-)
posted by persona non grata at 5:51 PM on July 17, 2006

I had read somewhere that every living creature would be killed by the initial neutrino flux way before the light from the supernova got to the earth (which is truly fascinating given how unreactive neutrinos are). But I may be misremembering. Does anyone have a reference on that?
posted by dopeypanda at 10:29 PM on July 17, 2006


Biological Effects of Stellar Collapse Neutrinos

Standard wisdom though is that it's the large amount of X-rays and Gamma-rays that would be the most lethal.
posted by ArkhanJG at 3:03 AM on July 18, 2006

"If the Sun blasts away half of its mass, or 10E30 kg, the earth would intercept 4.5 x 10-10 of the ejected mass, or 4.5 x 10E20 kg. This amounts to 1/13,000 the mass of the earth, but it would be moving at high speed. If it were moving at 10 per cent of the speed of light, its total kinetic energy would be 4 x 10E35 joules, or about 75 times the orbital kinetic energy of the earth and 4500 times the energy required to vaporize the earth."

To me this sounds like the Earth would not have time to vaporize completely before the expanding nova hit us carrying far more energy than the gravity well we're sitting in. A big chunk of what remains of the Earth should be blasted right out from the Sun's orbit. Time to get working on the mineshafts?
posted by Bletch at 8:53 AM on July 18, 2006

Thanks for the reference ArkhanJG. Sounds like what I remembered might actually be correct given that this paper is showing the possibility of mass extinctions due to nearby (!) stellar collapses. Now imagine the affect if the star was our own sun. I think the point of the neutrino flux killing us first is because it would reach the earth before the light since the stellar mass is essentially transparent to the neutrinos while the light is slowed (although the time difference is probably pretty small :-)
posted by dopeypanda at 4:33 PM on July 18, 2006

Cool link!
posted by BackwardsHatClub at 10:53 PM on July 18, 2006

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