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Powerful Supernova May Be Related To Death Spasms of First Stars

necro81 writes "The New York Times is reporting on a discovery from a team of UC Berkley researchers, who may have discovered the brightest stellar explosion ever observed. Observations of the cataclysmic explosion of a 100- to 200-solar-mass star began last September, based on data from the Chandra X-ray Observatory. The researchers believe that the explosion is similar to the death spasms of the first stars in the universe. The super-massive star's collapse is believed to have been so energetic as to create unstable electron-positron pairs that tore the star apart before it could collapse into a black hole — seeding the universe with heavier elements."

26 of 136 comments (clear)

  1. Kinda OT, but I thought I'd say... by Red+Flayer · · Score: 5, Funny

    Great summary. Lots of informative links, accurate and intriguing summary of the article(s). No gratuitous inflammatory question.

    Someone pinch me, I think I'm dreaming.

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    "Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
    1. Re:Kinda OT, but I thought I'd say... by Anonymous Coward · · Score: 3, Funny

      Look, though! there's an off-topic post!!!

  2. Oddity by tomstdenis · · Score: 3, Interesting

    They talk at the end about a star 7500 LY away that might "go supernova soon." It should probably be pointed out that it could have already gone supernova 6000 years ago and we'd not know about it.

    I guess they should say "might see if it went supernova soon."

    Tom

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    1. Re:Oddity by Nos. · · Score: 4, Insightful

      I think this is getting a bit pedantic. Sure, the light takes 7500 years to get here, thus it could have gone supernova quite some time ago, and the astronomers know this. It doesn't mean we have to speak about everything having occurred in the past... its all relative.

    2. Re:Oddity by JesseL · · Score: 4, Insightful

      Your post is based on the flawed premise that there exists some kind of objective time.

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    3. Re:Oddity by ls+-la · · Score: 3, Informative

      I guess they should say "might see if it went supernova soon."
      We know information cannot travel faster than the speed of light (or if you prefer, cannot reach outside the light-cone of the event). So if an event "happens" 7500 light years away, did it really happen before the light reaches us? In some sense, an event has not happened until we are inside its light-cone.
      Perhaps it "happens" when its light-cone intersects ours? The question with this interpretation is, where does our light-cone start?

      Time is relative, and over distances of at least the order of a light second (186,000+ miles), it is difficult to think about correctly.

    4. Re:Oddity by Orange+Crush · · Score: 5, Informative

      There is no such thing as synchronicity in this universe. Cause travels at the speed of light (or slower), gravity and relative velocity alter time and quantum states are ambiguous until observed. That star has a high probability of already having gone supernova, but this is meaningless in our frame of reference until the event is observable.

  3. Eta Carinae by tiluki · · Score: 5, Interesting
    What is more impressive about this story is the footnote of similar activity recently exhibited by Eta Carinae - a much closer star to us (well, 7500 light years). To quote the BBC article http://news.bbc.co.uk/1/hi/sci/tech/6633609.stm:

    Dave Pooley, at the University of California at Berkeley, said if Eta Carinae were to explode "it would be so bright that you would see it during the day, and you could even read a book by its light at night". Eta Carinae's death could be "the most spectacular star show in history." Is it just me, or does that sound a little bit too close...
    1. Re:Eta Carinae by Jugalator · · Score: 4, Informative
      It's not too bad unless we'd be unlucky and have a gamma radiation burst from it heading towards us.
      From here:

      The potential danger comes from the fact that explosions of massive stars generally emit jets of intense gamma radiation, among the most powerful and harmful forces in the universe. If Eta Carinae did explode and a jet was pointed in the general direction of the solar system, Livio said, Earth could be endangered. But because the gamma-ray jets tend to be relatively narrow, like the beam of a lighthouse, the odds are that the jet would miss Earth.

      So it's not too bad, it would probably just miss us.

      :-/

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    2. Re:Eta Carinae by vrmlguy · · Score: 4, Informative

      First, Eta Carinae is not visible to anyone north of 27 N, so in the US only people in or south of Miami will see it. In Africa, you basically have to be in a country that doesn't touch the Mediterranean Sea; while in Asia every country touching the Indian Ocean will see it, but not China or Japan. Among English-speaking countries, only Austrailia will have a great view, but the ozone layer will protect them (and the rest of the Southern Hemisphere) from direct radiation. "Scientists at NASA and Kansas University have determined that the supernova would need to be within 26 light years from Earth to significantly damage the ozone layer and allow cancer-causing ultraviolet radiation to saturate the Earth's surface. An encounter with a supernova that close only happens at a rate of about once in 670 million years(...) The new calculations are based largely on advances in atmospheric modeling, analysis of gamma rays produced by a supernova in 1987 called SN1987a, and a better understanding of galactic supernova locations and rates. A supernova is an explosion of a star at least twice as massive as our Sun." Since Eta Carinae is 300 times that distance, its blast wound need to be 90,000 times as energetic to be dangerous. A hypernova is about 100 times more powerful than a supernova, so there's plenty of margin of safety there.

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  4. Re:we should we believe the astrophysicists now? by Vendetta · · Score: 5, Insightful

    So you're saying it's a bad thing to revise theories based on new information or observations? There is a reason they are called "theories".

  5. Boom? by Jugalator · · Score: 3, Funny

    Big badaboom!

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  6. Re:Time-lapse video? by ls+-la · · Score: 5, Informative

    As far as I can tell from the articles, most of the observation was through means other than the optical spectrum pictures you're looking for (e.g. x-ray and IR pictures, spectroscopy, etc.). In fact, this supernova was so far away (240 million light years) that I'm not sure they could see it through optical telescopes. Most of a supernova's radiation (especially in something this violent) is emitted in the gamma ray range.

  7. Re:we should we believe the astrophysicists now? by PFI_Optix · · Score: 4, Insightful

    It's the revisions that make it science.

    Some scientists--and physicists can be especially guilty of this in my experience--place too much faith in their own knowledge and accept the current findings of science as absulute fact. They forget that science is fluid, always changing as new information enters the equation and each answer spawns new questions. Call it arrogance if you want; I think it's something less than that.

    In any case, what's the alternative? "God did it"? That may very well be true, but it doesn't answer the question of "how did it happen?"...which is what science seeks to explain.

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  8. Here's the NASA page. by u-bend · · Score: 5, Informative
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  9. Re:we should we believe the astrophysicists now? by Red+Flayer · · Score: 4, Informative

    Just goes to show you the arrogance of physicists- they claim answers and grandiose Standard Theories, but are frequently revising them because they mis things like accelerating expansion and 150SM supernova.
    Right. So we should not put blind faith in any theory, because it's open to being falsified. That's basic scientific method stuff.

    Isn't this what academic research is (in theory) all about? The search for better understanding, enabling us to revise our theories of how the universe (or some small subset of it) works?

    Find the simplest theory that fits all the observations. New data may mean you need a new theory, or that you need to revise your current theory. I don't understand the problem you have, unless it's just with the arrogance of some theorists who claim to have found the answer to Life, the Universe, and Everything. I say, let them be arrogant -- when they are disproved, they'll fall harder for it.
    --
    "Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
  10. Re:we should we believe the astrophysicists now? by Ambitwistor · · Score: 5, Insightful

    Why shouldn't we believe "the astrophysicists"? Did they lie to you? Gore your ox? Steal your candy? Pee in your breakfast cereal?

    After 70 years of computer simulations and observations they failed to predict this new kind of supernova.

    Yeah, so? There are infinitely many things that are true which scientists have yet to predict. Why are you under the impression that scientists are supposed to know everything? Even if they did know all the physics involved, you can still only make finitely many predictions in finite time.

    Its interesting to read speculations about degenerate lepton gases, but arent they just hand-waving again?

    "Again"? When were they "hand-waving" before? About what?

    Just goes to show you the arrogance of physicists- they claim answers and grandiose Standard Theories, but are frequently revising them because they mis things like accelerating expansion and 150SM supernova.

    That's a feature, not a bug. It's how science works! Physicists claim answers because they have answers. That doesn't mean they have ALL the answers, or they're always right. This is no different in astrophysics than in any other field of physics, or any other science, or in any other field of study, period. People know some things, they can predict some things, and sometimes they miss something or get something wrong. That doesn't mean that nobody knows anything or that experts have nothing useful to say.

    (By the way, accelerating expansion was in Einstein's theory from the start, but he took it out because there wasn't any evidence for it at the time.)

    I seriously don't understand your point of view, unless (as is likely) it's just flamebait. Every time something new is discovered, do you seriously run around disparaging whole fields of science just because the new thing wasn't predicted ahead of time? Or do you just have some bug up your nose about astrophysicists? It's not like they were even wrong about normal supernovae, they just didn't predict this new kind.

  11. E.L.E by TheSciBoy · · Score: 4, Interesting
    What I found interesting was that Eta Carinae apparently behaves the same way as the other star, which begs the question: could we survive the supernova? The explosions of stars certainly are powerful enough to destroy such delicate lives as ours if they are close enough. Question is, is Eta Carinae close enough?

    Now that's an Extinction Level Event.

    "Ooh! Aaah!" dead

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  12. Re:Actually, it's T E X A S by MontyApollo · · Score: 3, Informative

    From the article:

    The discovery was made by Robert Quimby, a University of Texas graduate student, who was using a small robotic telescope at McDonald Observatory near Fort Davis, Tex., to troll for supernovas
  13. That's no Supernova by MHz-Man · · Score: 3, Funny

    It was a precursor bomb! Looks like someone's copying the Shofixti's tactics.

  14. Re:Time-lapse video? by $RANDOMLUSER · · Score: 5, Informative

    Indeed. The best images are from the Chandra X-ray observatory. They have some animations here.

    --
    No folly is more costly than the folly of intolerant idealism. - Winston Churchill
  15. Re:Time-lapse video? by p_trekkie · · Score: 3, Informative

    Most of a supernova's radiation (especially in something this violent) is emitted in the gamma ray range.


    Actually, most of the radiation comes out as neutrinos. Only 1% comes out in forms we can detect at all...
  16. Re:we should we believe the astrophysicists now? by Hoi+Polloi · · Score: 4, Insightful

    How is trying to explain something based on the best current evidence arrogance? Are you saying people shouldn't ever believe anything or they should just ignore new info? Sorry but science is a continual learning process and unlike religion is constantly adjusting to new information and better explanations.

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  17. Re:we should we believe the astrophysicists now? by stewardwildcat · · Score: 5, Insightful

    As an astrophysicist I feel I should comment. First of all, 70 years of computer simulations later.... we are just beginning to be able to model a supernova with high enough resolution that we can "kind of" fit the observations without contrived scaling factors. This is also only being done in two dimensions and for the first few microseconds of a supernova. Models that hardly include all the physics involved are too much for the modern computational machine. Everytime we run a new model that includes more physics, they fit the data better and better. It is this way we discover what physics matters in the actual explosion. Since we cannot COMPLETELY model anything in real life on a computer all simulations are hand-wavy. Second, developing theories is very important. You use all of the available data and create a theory that can be tested and describes the current state of what you are studying. The real test of a theory is if it stands up to scrutiny. IF the "standard model" was so vague that no meaningful tests could be performed to prove the theory incorrect then it is a bad theory. Scientists prove things wrong, that is out job. We find situations where the current models do not describe the observations. That is scientific progress. We adjust our theories and learn about new physics. If gravity wasnt tested we would still be using Newtonian Gravity rather than General Relativity, which is still being worked on today (Gravity Probe B). Lastly, Astronomers have never observed a 150-200 Msolar supernova before. This is the first time we are able to look at what might have happened when the first stars formed. If we had seen a whole lot of these and had a perfect unified model then we wouldnt have to do science or discover things anymore. This is an exciting time as we have the most advanced instruments built by humans peering into the early universe discivering where we came from. I am always excited about new results, whether they be proven wrong or not, because we are always one step closer to understanding the world in which we live.

  18. Re:Time-lapse video? by imsabbel · · Score: 3, Informative

    Also:
    "
    The core implodes at velocities reaching 70,000 km/s (0.23c),[40] resulting in a rapid increase in temperature and density. Through photodissociation, gamma rays decompose the iron into helium nuclei and free neutrons. The conditions also cause electrons and protons to merge through inverse beta decay, producing neutrons and electron neutrinos. About 1046 joules of gravitational energy are converted into a ten-second burst of neutrinos.[41] These carry away energy from the core and accelerate the collapse, while some neutrinos are absorbed by the star's outer layers and begin the supernova explosion.[42]

    The inner core eventually reaches a density comparable to that of an atomic nucleus, where the collapse is halted. The infalling matter then rebounds, producing a shock wave that propagates outward. This expanding shock can stall in the outer core as energy is lost through the dissociation of heavy elements. However, through a process that is not clearly understood, the shock reabsorbs 1044 Joules[a] (1 foe) of energy, producing an explosion.[43]"

    You might have stumbled upon this part of the article while getting to the part you quoted. 10^44 joule ->explosion, 10^46 joule -> neutrino burst.
    ->only 1% is visible.

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  19. Old News... by rthille · · Score: 3, Funny


    Slashdot, 240 million years behind the times.

    (I should probably post this anonymously :-)

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