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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."
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.
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
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
Someday, I'll have a real sig.
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...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".
Big badaboom!
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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.
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.
120 characters for a sig? That's bloody useless.
Here's the NASA article about it.
u-bend
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
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.
Actually, my understanding was that astronomers are suggesting that this may be the first observed case of a type of supernova called pair-instability. The actual prediction of pair-instability supernovae was made decades ago - it's more that observations are catching up with predictions.
So, you seem to have gotten this exactly backwards.
As a bit of reading should also make clear, the reason that observations of this type of supernova are rare is that the conditions that favored the formation of stars capable of exploding this way have become rare as the universe has aged. They are expected to be far more common in the early universe, and it's hoped that the next generation of space telescope will be capable of viewing them (as it will see further, and thus earlier, into the universe).
______ This mind intentionally left blank.
Now that's an Extinction Level Event.
"Ooh! Aaah!" dead
Badgers, we don't need no stinking badgers! - UHF
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 supernovasIt was a precursor bomb! Looks like someone's copying the Shofixti's tactics.
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
Actually, most of the radiation comes out as neutrinos. Only 1% comes out in forms we can detect at all...
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.
It is by the juice of the coffee bean that thoughts acquire speed, the teeth acquire stains. The stains become a warning
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.
http://en.wikipedia.org/wiki/Nucleosynthesis its called nucleosynthesis. The reaction chains that fuse in the sun are called nuclear reaction networks. There is a lot of information available on this but Wikipedia gives a nice overview./
I hope you like physics, though. The chart of nuclides can be a bit confusing at first.
Is there a time-lapse video of this somewhere? The article I read only had an artist's rendering. Or when they say "observed" are they just talking about measurements?
Be veeery careful when asking for images on slashdot of anything that explodes, bursts, or has holes in it.
Table-ized A.I.
in the space.com article on this they mention that our own MilkyWay has a star about to go SuperMasive Nova at any time called Eta Carinae. Eta Carinae is about 7000 light years away so they say we are safe, but the Nova from last September eventually became brighter than it's own galaxy. So what i )BÇm wondering is even if we are safe from debris from this soon-to-be nova, what about an EMP from it?
The answer lies in whether you count neutrinos as radiation or not. What I should have stated in my original post was that the vast majority of the energy released in supernoave comes out in the form of neutrinos, which we have a really really hard time detecting...
Wikipedia is correct as to the source of photons that we detect. I counted neutrinos as a form of radiation in my earlier statement (since in my mind, that's what they effectively are), but neutrinos are not photons. Hence, there is no discrepancy. Basically, when we take the energy difference between the potential energy of a star before and after a Type II SNa (like this one) and check that against the energy we see from photons, we are only seeing 1% of the energy that should be coming out in all forms of light. The rest of the energy is believed to escape in the form of neutrinos.
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.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Do we know that 200 solar mass stars can exist within the Eddington limit? To summarize, higher mass will increase the energy output of the star's fusion reactions, and there's a point where this can more than counter the force of gravity. How would a star exceed this? Are collisions or mass accretion from another object likely?
Slashdot, 240 million years behind the times.
(I should probably post this anonymously
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Many thanks to you & the OP. You (both) are very tactful, as I skimmed right past the relevant Wiki section you noted so graciously. I'll try to do more exhaustive research before jumping in with questions next time.