A LIKELY STORY: An exploding star much like supernova 1987A, only much closer to home, may have initiated the collapse of the molecular cloud that would become the solar system, delivering newly synthesized material at the same time.
Image: NASA, ESA, P. Challis and R. Kirshner (CfA)
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One star dies, another is born. The remains of the old are gathered up, at least in some small measure, to become part of the new. That is the astronomical circle of life, the reason that stars have evolved through the eons, each generation incorporating new elements synthesized in the stars that came before. Unlike the earliest stars of hydrogen and helium, stars nowadays contain heavier elements passed down to them by their predecessors, such as carbon, iron and oxygen.
Aside from producing many of the elements that make up our planet and our bodies, the stellar cycle of birth and death appears to have spurred the formation of our solar system some 4.5 billion years ago. According to a new model outlined in a study in the July 1 issue of Astrophysical Journal Letters, a shock wave from an exploding massive star several light-years away probably triggered the collapse of the molecular cloud that would become our sun and planets.
Employing a bit of astrophysical forensics, researchers have located fingerprints of short-lived radioisotopes, long since decayed to more stable daughter elements, in primitive meteorites. For those radioisotopes to have been incorporated into primordial solar system bodies they must have been delivered, freshly synthesized, from some nearby cataclysm, whether a stellar explosion known as a supernova or an ailing star throwing off layers of material in less dramatic fashion.
Some researchers have hypothesized that the short-lived isotopes may have arrived in a shock wave strong enough to collapse the presolar cloud, thereby kick-starting the formation of the solar system and injecting newly synthesized material in one fell swoop.
But previous models had failed to deliver enough material to the nascent solar system to account for the observed prevalence of short-lived radioisotopes, says study co-author Alan Boss, a theoretical astrophysicist at the Carnegie Institution of Washington. Boss has been on the case for years, trying to solve the mystery of the solar system's formation. "Call it 'Crime Scene Solar System,'" he says. "It's a CSI show."
For years, Boss says, his models had relied on one kind of relatively thick shock front, based on the shell of material ejected in a planetary nebula. In the new study Boss and his Carnegie Institution colleague Sandra Keiser tweaked the modeled thickness and density of the shock wave. Varying the parameters of the shock front boosted the efficiency of the injection mechanism, to the point that the shock wave could indeed push enough material into the collapsing cloud to match observed radioisotopic levels. "Whammo, suddenly the injection efficiency went up quite a bit," Boss says, adding that the key was the incorporation of "more svelte, streamlined, slimmed-down shock fronts."
The svelte shock front in Boss's model better resembles a supernova spurred by the collapse of a massive star's core than it does an alternative proposed explanation, an expanding shell of material ejected from an aging type of star called an asymptotic giant branch (AGB) star. "There really is a good reason for thinking that a supernova did it," Boss says.
Based on encounter probabilities alone, the supernova mechanism appears more likely than a push from an AGB star, says Gary Huss, a cosmochemist at the University of Hawaii at Manoa. "A much wider variety of massive stars appear to be viable sources than AGB stars, most of which do not produce enough iron 60," one of the short-lived radioisotopes present in the early solar system, Huss says.
He notes that the new paper reinforces a number of previous studies pointing to a massive supernova as the source of short-lived elements in the early solar system. "I am comfortable with this conclusion, but the case is by no means closed," Huss says. "It will take many more studies like the one in this paper, many more observations of stars, star formation and stellar explosions, and many more models of stellar nucleosynthesis to close this case for good."
Of course, there is no reason that some mechanism could not have delivered the radioisotopes shortly after the presolar cloud began to collapse for a totally unrelated reason. "It's mostly economy of hypotheses" to link both actions to a common source, Boss says. "It's nice to do both things at once, and it does seem to work."
As with detectives working more conventional cold cases, Boss continues to apply better technology to the task. He is now moving from two- to three-dimensional modeling, a process that requires far more computing power but that provides better clues to solving the mystery of the solar system's formation once and for all. "Mother Nature did it," Boss says. "We know who the perp is, but we want to know how she did it."
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22 Comments
Add CommentA wow of an article. How exciting to have found a hypothesis that seems to work. How exciting to have ever-better tools and computers to look for an even better one.
Reply | Report Abuse | Link to thisany ideas of where the remnant of this supernova might be?
Reply | Report Abuse | Link to thisDo we really know how the Solar System was formed? All we have at present are assumptions piled on top of assumptions, and no real evidence . According to the Electric Universe Theory, the Sun captured Jupiter, Saturn, Uranus, and Neptune, all of which were originally Brown Dwarfs. The Earth , along with Mars and Venus, were once satellites of Saturn, a mini system captured by the Sun.
Reply | Report Abuse | Link to thisWhat is 'real' evidence? Seems the author has presented evidence. I'm not sure what differentiates 'real' evidence from just plain evidence. Kind of like 'preconditions' for negotiations.
Reply | Report Abuse | Link to thisbpuharic - The only evidence I saw was the suggestion of:
Reply | Report Abuse | Link to this"fingerprints of short-lived radioisotopes, long since decayed to more stable daughter elements, in primitive meteorites."
I'm unclear as to how its determined that only the hypothesized SN modeled could have produce the short-lived radioisotopes that could only have produced the detected stable elements found in meteorites... Seems like somewhat scanty evidence to me, but what do I know?
According to "Cloudy with a Chance of Stars" by Erick T. Young which appeared in the February 2010 of SCIENFIC AMERICAN (and I have seen the same idea elsewhere) the pre-solar cloud fragments into multiple stellar embryos. Could the "fingerprints of short-lived radioisotopes" in the current article also be used to identify stellar systems which evolved from the same events as our solar system?
Reply | Report Abuse | Link to thisDon B of Ferndale - Interesting.
Reply | Report Abuse | Link to thisOK, reading the referenced article abstract (unwilling to pay $9 to buy the ApJ Letters), it appears that a specific unstable isotope of iron that would have decayed if it had not been immediately incorporated into solids has been found within Solar system meteorites. According to the described parametric modeling of shock wave densities, only a nearby core collapse supernova could produce the speeds necessary to transport sufficient quantities to produce the amounts detected in meteorites.
So, I'd guess that any other stellar systems that were produced by the same SN would require a sample of their meteorites, which would contain a different amount of this iron isotope, depending on distance from the SN. However, this could not distinguish meteorites produced by other, similar SN. In any case, meteorite samples from other additional stellar systems would have to be collected and identified. I understand this might be possible, but would certainly be unlikely.
Our solar system most likey has some material from a few(previous) Super Nova? What we have to ask is, when a Supernova (goes Nova) does it; 1) have planets(?), 2) detroy those planets, 3) launch the planets out of the current solar system, 4) do these planets gather dust and form bigger planets or their own solar systems????
Reply | Report Abuse | Link to thisReading some of Professor Oliver Manuel's ideas, the SuperNova was our very own sun! Its not a popular theory but when you follow Manuel's detailed line of reasoning (cradle of nuclides, neutron-neutron repulsion as energy source etc) it makes sense to me.
Reply | Report Abuse | Link to thisES-101 - 98.8% of the Solar system's estimated mass is contained within the Sun. Any material from prior supernovae incorporated into the the current Solar system probably came from exploded stellar masses, regardless of the disposition of any planetary material. Casual examination of SN nebulae seem to indicate that residual atomic and molecular masses are retained within the general vicinity of the explosion.
Reply | Report Abuse | Link to thisWhat is a "shock wave" ? Is it faster than c ?
Reply | Report Abuse | Link to thismorp - With the 4th of July last week, if you've ever been near a firecracker or other explosion you may have felt a shock wave or pressure wave transmitted through the atmosphere or even the ground. For a more complete discussion see:
Reply | Report Abuse | Link to thishttp://en.wikipedia.org/wiki/Shock_wave
Shock waves are often slower than the speed of sound (exceeding that threshold produces an audible shock wave) but I think always slower than c.
I wonder why Scientific American publishes now an exact opposite theory to what they published in April 2003," Why and how planets rotate"
Reply | Report Abuse | Link to thisI remember also that the "shock waves" from this article cannot be sound waves
A theory must be based on known facts, in other words , what you see is what you get! If a theory does not agree with experience, it's wrong!
Reply | Report Abuse | Link to this
Reply | Report Abuse | Link to thisSome writers agree the proton is a wave,others do not understand. That the mass of the proton depends on the name of the experimenter and on the measuring method is precisely a proof of its wave nature.
Big forces that hold protons together do not exist
all nuclei are ,like the proton,solutions of Maxwells' equations
The most fundamental characteristics of matter are found not by hypotheses but in atomic spectra; They are very simply explained by wave theory But "scientists" can not explain atomic spectra after a century of rechearch , another proof of the wave nature of matter and of ligth.
I dislike Models that are finally made to work and prove something. Since a supernova has the kinetic heat energy of a galaxy, millions of new stars will start forming from the hot blown gas of a supernova. ejecta with unstable iron isotope in the solar system meteorites proves rapid star formation. Surely our sun is not one ancient supernova but in a sea of space supernova blasts that happen about every 100 years in the galaxy, long enough to mix the ejecta between many different supernovas and not lose the radioactive iron before it became incorporated inside the meteorites.
Reply | Report Abuse | Link to thisLOL, "real" evidence what an idiot. Why don't we physically go capture the answer so its real evidence, maybe get a big net and go capture the answers. Lets not make assumptions or hypothesize based on centuries of scientific precedent and fact all that stuff was a waste. They were just empty assumptions. You're the kind of person that sits in a math class and bitches about, "how i'll never use this knowledge later in my life." If a stove is on and its hot do you touch it? No because you trust your scientific knowledge to know that you will get burnt. You have fun burning yourself because apparently scientists are hobbyists.
Reply | Report Abuse | Link to thisAnd do intellectuals actually say "c" instead of speed of light in plain conversation? Well im hungry now so im gonna go replenish my carbohydrates and amino acids and protein and maybe consume some carbonated H2O formula. Oh yeah, im going to...."eat." Anyway i don't think that matter being injected into anything via a supernova blast would be able to surpass the speed of light because its still just moving matter. Simple matter like carbon and iron things i wouldn't think would be moving that quickly.
Reply | Report Abuse | Link to thisHolySchmidt - I understand, from reading journal articles, that real physicists do, but then they really aren't the intellectuals they think they are. They even use the term z in open text to represent velocity, I think.
Reply | Report Abuse | Link to thisI'm no physicist, but I wonder if an energy wave being transmitted through intragalactic spacetime might be able to reach the speed of light. I think a supernova 'shock wave' self-propagates through a 'vacuum'. But I'm just guessing...
Personally I think the sealed chondrule structures (not mentioned here) formed as dense blobs of melted heavy elements, produced by the supernova directly from the final fusion of its stellar material, cooled.
You stated: "That the mass of the proton depends on the name of the experimenter and on the measuring method is precisely a proof of its wave nature."
Reply | Report Abuse | Link to thisI'm not sure what you're referring to, but I've had some similar thoughts regarding the mass ratings attributed to identified fundamental particles.
http://en.wikipedia.org/wiki/File:Standard_Model_of_Elementary_Particles.svg
This chart shows the 16 fundamental particles identified by the Standard Model of Particle Physics, including the assigned values of their mass, charge and spin characteristic properties. If I recall correctly, these may be average values.
There are 3 generations of matter (Fermions) including quarks, neutrinos and electrons. The gen 1 quarks are up & down; gen 2 charm & strange, gen 3 top & bottom. The only distinction between each generation is the amount of mass estimated from their momentum observed during particle collider experiments in which they are detected.
The first generation of matter was detected in accelerator experiments colliding atoms together. Their high rest mass limited the velocity that could be applied to atoms, producing lower velocity collisions that detected only the lower mass gen 1 quarks.
Subatomic particles (protons) have been accelerated in later collider experiments. Their lower rest mass allowed higher velocity collisions, initially producing only the higher mass gen 2 quarks.
Newer, higher energy particle accelerators allowed higher velocity collisions between subatomic particles, producing only the highest mass gen 3 quarks.
Particle physicists consider that higher energy collisions are necessary to produce the higher mass quarks. However, since the mass attributed to detected quarks is derived from the observed momentum produced by higher velocity collisions, I suggest that the higher velocity imparted to the test particles produces the greater momentum observed in collision products. In other words, perhaps the only difference between the 3 generations of matter is the velocity imparted to test particles!
I expect that the LHC will eventually 'discover' even higher mass gen 4 fermions...
Of course, I'm just guessing the obvious - surely the much more knowledgeable particle physicists couldn't have been fooled so easily...
You stated: "That the mass of the proton depends on the name of the experimenter and on the measuring method is precisely a proof of its wave nature."
Reply | Report Abuse | Link to thisI'm not sure what you're referring to, but I've had some similar thoughts regarding the mass ratings attributed to identified fundamental particles.
http://en.wikipedia.org/wiki/File:Standard_Model_of_Elementary_Particles.svg
This chart shows the 16 fundamental particles identified by the Standard Model of Particle Physics, including the assigned values of their mass, charge and spin characteristic properties. If I recall correctly, these may be average values.
There are 3 generations of matter (Fermions) including quarks, neutrinos and electrons. The gen 1 quarks are up & down; gen 2 charm & strange, gen 3 top & bottom. The only distinction between each generation is the amount of mass estimated from their momentum observed during particle collider experiments in which they are detected.
The first generation of matter was detected in accelerator experiments colliding atoms together. Their high rest mass limited the velocity that could be applied to atoms, producing lower velocity collisions that detected only the lower mass gen 1 quarks.
Subatomic particles (protons) have been accelerated in later collider experiments. Their lower rest mass allowed higher velocity collisions, initially producing only the higher mass gen 2 quarks.
Newer, higher energy particle accelerators allowed higher velocity collisions between subatomic particles, producing only the highest mass gen 3 quarks.
Particle physicists consider that higher energy collisions are necessary to produce the higher mass quarks. However, since the mass attributed to detected quarks is derived from the observed momentum produced by higher velocity collisions, I suggest that the higher velocity imparted to the test particles produces the greater momentum observed in collision products. In other words, perhaps the only difference between the 3 generations of matter is the velocity imparted to test particles!
I expect that the LHC will eventually 'discover' even higher mass gen 4 fermions...
Of course, I'm just guessing the obvious - surely the much more knowledgeable particle physicists couldn't have been fooled so easily...
Webmaster: Again, please delete inadvertent duplicate post (#20 above) Thanks.
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