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New Class of Stars Are Totally Metal, Says Astrophysicist

Posted by samzenpus on from the hit-the-lights dept.

KentuckyFC writes Stars form when clouds of gas and dust collapse under their own gravity, generating enough heat and pressure to fuse the atoms inside them together. When this cloud of dust and gas is the remnants of a supernova, it can contain all kinds of heavy elements in addition to primordial hydrogen, helium and lithium. Now one astrophysicist has calculated that a recently discovered phenomenon of turbulence, called preferential concentration, can profoundly alter star formation. He points out that turbulence is essentially vortices rotating on many scales of time and space. On certain scales, the inertial forces these eddies create can push heavy particles into the calmer space between the vortices, thereby increasing their concentration. In giant clouds of interstellar gas, this concentrates heavy elements, increasing their gravitational field, attracting more mass and so on. The result is the formation of a star that is made entirely of heavy elements rather than primordial ones. Astrophysicists call the amount of heavy elements in a star its "metallicity". Including preferential concentration in the standard model of star formation leads to the prediction that 1 in 10,000 stars should be totally metal. Now the race is on to find the first of this new class of entirely metal stars.

119 comments

  1. Look in Decibel Magazine by Anonymous Coward · · Score: 5, Funny

    or Kerrang! They're full of metal stars

    1. Re:Look in Decibel Magazine by Anonymous Coward · · Score: 0

      Yeah, my first thought when reading this headline was also along these lines. =)

  2. Totally Metal by Guy+From+V · · Score: 3, Funny

    When did Nathan Explosion become an astrophysicist?

    1. Re:Totally Metal by HairyNevus · · Score: 1

      No, no, no. His stardom has finally reached the magnitude that it has become observable in outer space, by astrophysicists. Given his take on Shakespeare, I doubt he'd make a good astrophysicist.

      --
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    2. Re:Totally Metal by Anonymous Coward · · Score: 0

      Gives a new meaning to the term "Heavy Metal"! Someone's going to have to write a song about this... :-)

    3. Re:Totally Metal by Guy+From+V · · Score: 1

      Well, he does wear glasses sometimes.

  3. Made of Led? by tomhath · · Score: 2

    First metal star should be named after them.

    1. Re:Made of Led? by TarPitt · · Score: 5, Insightful

      name it Ozzy

      --
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    2. Re:Made of Led? by Anonymous Coward · · Score: 0

      Iron Butterfly and get off my lawn!

    3. Re:Made of Led? by Anonymous Coward · · Score: 0

      A metal star would be interesting. Led Zeppelin were dull.

    4. Re:Made of Led? by mrbester · · Score: 2

      Lemmy.

      --
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    5. Re:Made of Led? by Anonymous Coward · · Score: 0

      How about Johnny? (Rotten)

  4. Ouch... by djupedal · · Score: 1

    Wow - a new low in poorly written summaries, sorry.

    1. Re:Ouch... by killkillkill · · Score: 1

      Are you kidding? This isn't even in the lower quartile of bad summaries here. If it were among the worst of the summaries, you wouldn't even know TFA had something to do with stars.

  5. Hydrogen is metal! by Anonymous Coward · · Score: 0

    Nuf said.

    1. Re:Hydrogen is metal! by dltaylor · · Score: 3, Informative

      Helium is not!

      If you read the article, however, it would point out that astronomers use a skewed definition of "metal", as any element heavier than lithium.

      At birth, stars contain little helium, but is is constantly generated by fusing hydrogen.

      If you start with metals like sodium and potassium, plus what we normally call non-metals, like carbon and oxygen, then you won't get around to generating helium until you fuze something radioactive that emits an alpha particle.

  6. Star? by Anonymous Coward · · Score: 0

    If it's all metal, shouldn't it be a planet?

    1. Re:Star? by MightyMartian · · Score: 4, Insightful

      Stellar fusion can occur with atomic elements up to iron. There are a number of metals that are lighter than iron. If I'm reading this right, stellar fusion could conceivably be triggered by heavier metallic elements if they were "selected for" by the properties of vortices during the formation process.

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    2. Re:Star? by Zcar · · Score: 4, Informative

      Additionally, in astrophysics the term "metal" includes many elements which are not metals in any other field. Astrophysically, metals are any element other than hydrogen or helium, so in addition to ordinary metals like sodium and lithium non-metallic elements such as carbon and oxygen are counted as metals.

    3. Re:Star? by Zcar · · Score: 1

      To be clear, there are some varying definitions out there from anything other than hydrogen to anything other than hydrogen, helium, or lithium. Other than hydrogen and helium is the definition I've run across most often.

    4. Re:Star? by Anonymous Coward · · Score: 0

      I am OP

      I was thinking more of the fact that it is solid, I think of stars as made of gas. But if there is fusion going on, then it wouldn't be solid, I suppose, and it would make sense to call it a star.

    5. Re:Star? by Anonymous Coward · · Score: 0

      I think of stars as made of gas.

      Plasma.

    6. Re:Star? by Anonymous Coward · · Score: 0

      Watch any red carpet interview, and you will quickly learn that stars are all gas, not plasma.

    7. Re:Star? by nedlohs · · Score: 1

      1. In astronomy all the elements except for Hydrogen and Helium are in the category "metals", so no.
      2. In astronomy planets are things which orbit stars (plus some other criteria), so no.

    8. Re:Star? by lgw · · Score: 1

      The best part of which is that hydrogen is, technically, a metal! (It doesn't act like one in water-based chemistry, but it does in some other contexts.)

      Hehe, astonomers, they're in their own world.

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    9. Re:Star? by dave420 · · Score: 1

      2. Not entirely. There are planets without stars, and there are stars which orbit stars (well, stars which orbit a barycentre between itself and another star, which may or may not be inside the other star).

    10. Re:Star? by AJWM · · Score: 1

      Yep. Carbon, nitrogen, oxygen .. all metals. To an astrophysicist, we're not made of meat, we're made of metal.

      (Okay, there's a fair bit of hydrogen in our mix, too.)

      --
      -- Alastair
    11. Re:Star? by cyberchondriac · · Score: 1

      You're thinking in terms of terrestrial temperatures. As gravity and friction do their thing as the elements clump together, the temperature rises -pardon the pun- astronomically.

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  7. metal up your ass! by globaljustin · · Score: 1

    **bangs head**

    --
    Thank you Dave Raggett
  8. found long ago by Anonymous Coward · · Score: 0

    First star has been found. Named Fornax-RitchieBlackore837

  9. "star stuff" by globaljustin · · Score: 2

    Every time I hear about a (cool) new kind of star like this i get all teh happi feelz

    It reminds me of the Cosmos where Sagan elucidates how everything and everyone we've ever known is made of "star stuff" & our composition reflects our star's composition

    So...what kind of planets & planetoids would a **METAL STAR** make???

    --
    Thank you Dave Raggett
    1. Re:"star stuff" by Anonymous Coward · · Score: 1

      Hard Rock, presumably.

    2. Re:"star stuff" by Guy+From+V · · Score: 1

      Astrophysicist Dr. Brian May might have some workable theories.

    3. Re:"star stuff" by Anonymous Coward · · Score: 0

      So...what kind of planets & planetoids would a **METAL STAR** make???

      This kind.

  10. We have a name for these already... by Guano_Jim · · Score: 5, Funny

    ... they're called Class \m/ stars.

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    1. Re:We have a name for these already... by Anonymous Coward · · Score: 0

      I vote we classify them as doomstars.

    2. Re:We have a name for these already... by Vitriol+Angst · · Score: 1

      I'd say all we need to do to find the Metal stars is to look for those that have their fusion output turned up to 11.

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  11. Metal? by Anonymous Coward · · Score: 1

    That totally rocks!!!!

  12. Totally Metal Stars by Anonymous Coward · · Score: 0

    Tuesday, Tuesday, Tuesday! Come see the Totally Metal Stars including Megadeth, Metallica, Slipknot and dozens of other head banging, screaming metal bands! Tickets on sale now!

  13. So, it's true by Anonymous Coward · · Score: 0

    Star systems really are just large-scale atoms and those metal stars are the nucleus.

    1. Re:So, it's true by wonkey_monkey · · Score: 1

      Err, no. None of that is true, and this news doesn't make it any truer.

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    2. Re:So, it's true by MightyMartian · · Score: 1

      No, they really are not. Gravity has very little effect at the atomic level, but at the level of solar systems is the primary force.

      --
      The world's burning. Moped Jesus spotted on I50. Details at 11.
    3. Re:So, it's true by mysidia · · Score: 1

      No, they really are not. Gravity has very little effect at the atomic level, but at the level of solar systems is the primary force.

      No, they might very well be. But it is just speculation --- accomplished science neither shows whether they are or not. It's just speculation, either way.

      Iif you subscribe to the Bohr model of an atom... our solar systems are a larger scale universe's atoms, then the force we call "Gravity" could be the larger scale universe's electromagnetic force, and then Earth would be an "electron" orbiting the Sun, which would be our nucleus.

      The laws of chemistry and physics applicable to the universe at the different scale would have to be quite different.... which is not to say that our solar systems are not another universe's fundamental particles.

    4. Re:So, it's true by dave420 · · Score: 1

      The Bohr model is not an accurate description of atoms, so it's pointless to try to compare anything to it and claim you are comparing to actual atoms.

    5. Re:So, it's true by MightyMartian · · Score: 1

      Huh? It's been demonstrated many times in many different ways that gravity is by far the weakest of the fundamental interactions. Gravity makes little difference at the atomic and subatomic levels. Atoms are not mini-solar systems. The forces that bind atomic nuclei and bind electrons to atomic nuclei are fundamentally different from gravity. Here's a tip; at least at the temperatures and densities you will find virtually everywhere in the universe today; gravity, electromagnetism, the strong and weak interactions are very different.

      Christ pal, your claim was known to be rubbish eighty years ago. To see someone making a claim that atoms are mini solar systems in the 21st century isn't too far different from someone claiming the Sun orbits the Earth.

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    6. Re:So, it's true by mcswell · · Score: 1

      Sure. And if you subscribed to the Ptolemaic model of the solar system, then I suppose you'd have some other theory of atoms.

    7. Re:So, it's true by mysidia · · Score: 1

      To see someone making a claim that atoms are mini solar systems in the 21st century isn't too far different from someone claiming the Sun orbits the Earth.

      You're either a nasty troll, or you just aren't paying attention at all. The claim was not that atoms are mini solar systems: quite the opposite; that our solar systems themselves are subatomic particles at a grander superscale: a superscale at which our entire solar system weighs something like 3 × 10^-29 grams. And the passage of time from our point of view is such that when we perceive 1 second of time passes, at the superscale, approximately 10^-29 seconds has elapsed.

      Our "gravity" may be analogous at the superscale, to what we call the electromagnetic force. And at this larger scale, our stars would essentially be the core of the atomic unit, and the cloud of large rocks orbiting them would be analogous to electrons.

      Since, the whole thing is that, our universe is essentially at a "quantum level" compared to whatever is happening at the "super scale"; we have no way of reasoning about what the laws of physics would be at the super scale. There may well be new forces and spatial dimensions emerging at the larger scale, analogous to our weak forces such as gravity.

  14. One slight problem with that ratio... by pla · · Score: 5, Interesting

    Let's take TFA at face value, and assume one in 10k stars start their evolution as count as "metallic" stars.

    Hydrogen main sequence stars burn for a a few million years (for the class O supergiants) to literally trillions of years (for the class M all-but-failures). Helium burning, in a star with sufficient mass, lasts between a few hundred thousand to a few dozen million years.

    The subject of TFA starts after helium burning normally finishes - Next on a typical star comes carbon, lasting for only a few hundred years; Then comes neon lasting for a single year, oxygen at half a year, and silicon finishes its run in a single day.

    So whether or not a star begins life with a high concentration of trans-lithium metals, it will have a very, very short lifetime; That one-in-ten-thousand creation ratio therefore reduces to more like one-in-a-trillion among those stars still shining in our nighttime sky.

    1. Re:One slight problem with that ratio... by ArcadeMan · · Score: 4, Funny

      You're right, heavy metal stars usually have short lifespans.

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    2. Re:One slight problem with that ratio... by Anonymous Coward · · Score: 0

      Tell that to Metallica who just rocked Glastonbury, again, the other week

    3. Re:One slight problem with that ratio... by Kaenneth · · Score: 2

      ... Metallica isn't real metal.

    4. Re:One slight problem with that ratio... by Anonymous Coward · · Score: 0

      +1 if only I had mod points

    5. Re:One slight problem with that ratio... by I'm+New+Around+Here · · Score: 1

      You apparently don't know that Metallica lost a member very early in their career. So, yes, metal stars do flame out early.

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    6. Re:One slight problem with that ratio... by rahultyagi · · Score: 2

      you are assuming that by "metal" they mean iron etc. all the examples that you cite (except H and He) are "metals" by astrophysicists' definition.

    7. Re:One slight problem with that ratio... by theguyfromsaturn · · Score: 1

      I know very little of astronomy, but I have to wonder at the reason why each of the fusion cyles is shorter... is it only because some intrinsic property of the heavier fuel? I had alsways assumed that the fact that there is only a fraction of the original star mass that makes it to Carbon, and only a fraction of that to each successive element in the list what the root cause the the exponential decay in life expectancy of each fuel source. If that is the case, the reason that each cycle is shorter is the lack of fuel. Now, what if ALL the star is made of heavier fuel from the start? Shoud we still expect a ridiculously short fusion time for the initial fuel? If the answer is no, shouldn't such a star be able to shine for at least a few million years?

      This is an honest question by someone who wants to know, not a criticism of the parent post.

      --
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    8. Re:One slight problem with that ratio... by Anonymous Coward · · Score: 0

      Hydrogen main sequence stars burn for a a few million years (for the class O supergiants) to literally trillions of years (for the class M all-but-failures).

      Very well put. Also it takes more and more energy in order to fuse these heaver elements. That is why fusion stops at iron, it actually takes more energy to fuse than you get back. The big problem is that ALL stars burn these heavier elements, so these "special" stars won't be easy to find by looking at their spectral alone. Something else is going to be needed to say this star is normal and this star is a metal star.

    9. Re:One slight problem with that ratio... by kenwd0elq · · Score: 4, Informative

      Fusion of hydrogen into helium produces a LOT of energy. Fusion of helium into carbon produces less. In physics terms, it's the "packing fraction" curve, which can show you what energy you'd get out if you fuse elements together.

      Iron is at the bottom of the packing fraction curve; when you fuse other stuff into iron, you're getting out the dregs of the fusion energy, partly because it takes higher and higher pressures and temperatures for fusion to occur for heavier elements.

      When you get to the pressure and temperature points where iron fuses into still heavier elements, it begins to EXTRACT energy - from the core of the star. Stars exist in a delicate balance between the heat and pressure that tries to blow them apart, and the gravity that tries to crush them together. Take heat OUT of the core of the star, and there's less internal pressure - and gravity starts to win. The core will collapse, generally abruptly, and a crushing "rebound effect" will accelerate the heavy fusion, extracting MORE energy, leading to a core collapse supernova. The star explodes, leaving a black hole or pulsar at the center and blasting a lot of the stellar material back into space.

      Which is where we got the iron for our blood, or the gold for our jewelry - blasted out of a supernova. Probably MANY of them.

    10. Re: One slight problem with that ratio... by Anonymous Coward · · Score: 0

      I'm glad gravity wins

    11. Re:One slight problem with that ratio... by Anonymous Coward · · Score: 0

      I have some doubts if your length estimates are accurate. Usually as a star progresses along it gets brighter and brighter, which indicates the core fusion rate is going up as it gains density and thus more pressure.

      But if you start with an all metal star straight off, wouldn't it potentially start with a more sedate initial burn speed?

      Admittedly even then their time to shine is probably still fairly limited, but it might not be quite as bad as you described then.

    12. Re:One slight problem with that ratio... by Charliemopps · · Score: 1

      They used to be, then they got inflated as they burned up all the elements that made them in the first place.

    13. Re:One slight problem with that ratio... by Draugo · · Score: 1

      What kenwd0olq said. If you want somewhat more detailed explanation listen to Richard Pogge's excellent Astronomy 162 lecture series and specifically the lectures about death of low and high mass stars (might be somewhere around lectures 14 and 15 but that's just from memory and I'm not sure about that at all).

    14. Re:One slight problem with that ratio... by sillybilly · · Score: 1

      By the way nickel 62 is the ultimate symbol of death, the atom with the most binding energy per nucleon, and not Iron. I had a job where I extracted cobalt from nickel, and I was thinking this is how the world is gonna end, extracting high energy stuff from the low energy nickel 62 waste. Iron 56 is often cited instead of nickel 62, and it's close in binding energy, but not top, and more abundant because of units of 4, alpha radiation of helium atoms predominate as a unit in building up heavier elements, and 14x4=56, while 15.5x4=62. But nickel might be more abundant in the core of the Earth or in satellites than in the litosphere, probably because it's more noble or less reactive, it also only goes to divalent not trivalent as iron, so it turns to the metallic form easier and sinks deep easier.

    15. Re:One slight problem with that ratio... by Anonymous Coward · · Score: 0

      ding ding ding
      winner

    16. Re:One slight problem with that ratio... by Anonymous Coward · · Score: 0

      Anybody have an account for arXiv.org? Should go email him about that issue.

    17. Re:One slight problem with that ratio... by sillybilly · · Score: 1

      Actually the http://en.wikipedia.org/wiki/N... wikipedia page says, even though highest binding energy of all known nuclides per nucleon, Ni 62 per se is very rare, even amongst nickel, because of the difficulty of producing it by neutron capture. Fe 56 has the lowest mass per nucleon, and this whole thing is not a contradiction (lowest mass meaning lowest total energy, or highest binding energy) because when counting nucleons we confuse/confound neutrons with protons. Ni 62 contains a higher ratio of neutrons to protons than Fe 56, and as neutrons weigh more than protons, Ni 62 is higher mass per nucleon. According to the article, "the mass per nucleon of Fe 56 is 930.412 MeV/c2, Ni 62 is 930.417 MeV/c2, but if one looks only at the nuclei proper, without including the electron cloud, 56Fe has again the lowest mass per nucleon (930.175 MeV/c2), followed by 60Ni (930.181 MeV/c2) and 62Ni (930.187 MeV/c2)." The binding energy wikipedia page http://en.wikipedia.org/wiki/N... says that, because neutrons are higher energy than protons, it may be possible to convert Ni 62 back to Fe 56, but only under conditions where entropy considerations require that not the lowest energy states be the most occupied ones. Also the wikipedia neutron page http://en.wikipedia.org/wiki/N... says the decay energy of a free, unbound neutron is 0.782343 MeV but "When bound inside of a nucleus, the energetic instability of a single neutron to beta decay is balanced against the instability that would be acquired by the nucleus as a whole if an additional proton were to appear by beta decay, and thus participate in repulsive interactions with the other protons that are already present in the nucleus. As such, although free neutrons are unstable, bound neutrons in a nucleus are not necessarily so. The same reasoning explains why protons, which are stable in empty space, may transform into neutrons when bound inside of a nucleus."

      So what is the most stable "death" of matter, Fe 56 or Ni 62? Which one has the lowest mass per "stuff", and counting nucleons is not a proper way of accounting stuff, it's like asking what has the lowest energy per energy invested, at, say the 3 Kelvin background temperature of the Universe, where entropy dictates the lowest states to be predominantly occupied (including a stable electron cloud), unlike in the core of a super hot supernova? Can anyone answer?

    18. Re:One slight problem with that ratio... by sillybilly · · Score: 1

      Also, suppose there was a big bang, and all matter started out as hydrogen at 3 K temperature. What's the equilibrium temperature when all the hydrogen is converted to Ni 62 or Fe 56? It's certainly no longer 3K, unless the conservation of energy does not stand. If there is such a thing as thermal heat death of the Universe as predicted by Thompson, (Lord Kelvin) and the 2nd law of thermodynamics, this equilibrium heat death may be of a very hot temperature, at which not the most stable nuclide would release the most free energy, i.e. not the most stable nuclide at 3K, but most stable at that hot temperature, and this may be neither Fe 56 nor Ni 62. If the 2nd law stands forever, that is, and is not violated by some Maxwell demon-like microprocess that goes on forever, that is a perpetuum mobile of the 2nd kind, without having to burn up and convert any more hydrogen to higher elements to keep going and going ad perpetuum. That could mean life ad perpetuum, meaning everlasting, permanent.

    19. Re:One slight problem with that ratio... by Anonymous Coward · · Score: 0

      Once iron is fused in a star, it has seconds to live.

      This seems like psuedo-science.

  15. Using a different definition of "metal" by jcochran · · Score: 4, Informative

    What astronomers mean for the word "metal" isn't what the rest of us mean.

    As mentioned in the link to Metallicity, the all metal stars could be composed of carbon, nitrogen, oxygen, etc. Basically anything other than hydrogen and helium.

  16. Isnt Hydrogen a Metal? by oic0 · · Score: 1

    Doesn't seem that far fetched when you consider hydrogen is a metal....

    1. Re:Isnt Hydrogen a Metal? by Anonymous Coward · · Score: 0

      it's not, it's the sole non metal on that side of the table. Still a valid point though that there's a lot of metals most people dont consider metals and metalloids that there can be that still have exothermic fusion reactions possible. Theres about 50% more of them than non metals before iron

  17. Imploding stars? by Tablizer · · Score: 1

    At first I thought this was about Justin Bieber.

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  18. The Logan-Preston.Esq. class star? by Chas · · Score: 1

    *Air Guitar*

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    1. Re:The Logan-Preston.Esq. class star? by Anonymous Coward · · Score: 0

      Your lowid is showing.

    2. Re:The Logan-Preston.Esq. class star? by Chas · · Score: 1

      I'll do my bhttp://slashdot.org/comments.pl?sid=5360761&cid=47380539#est to keep it tucked back.

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  19. Heavy by vanyel · · Score: 1

    Now that's heavy metal I could actually get into...

  20. Fission? by countach · · Score: 1

    Um.. but no energy could be released from such a star surely, since fusion of anything heavier than iron produces no energy, but actually takes energy. The only way it could produce energy then would be fission. But I'm skeptical about whether a star in such circumstances would really light up, or would just be a sphere of dead metal.

    1. Re:Fission? by Anonymous Coward · · Score: 0

      It's really a phrasing technicality, as although most people dont think of them as such 15 of the 25 elements prior to Iron are considered metals or metalloids.

    2. Re:Fission? by gstoddart · · Score: 1

      Um.. but no energy could be released from such a star surely, since fusion of anything heavier than iron produces no energy

      Right, iron Fe, atomic mass 26.

      Lithium, for instance, has an atomic mass of 3. Lithium is a metal. I'm sure there are other metals below 26, Sodium comes to mind (atomic mass of 11).

      So, based on the assumption that heavier than iron means fission, but less than iron fusion, there's still room for fusion, no?

      I think this is fusion, but with a slightly different chemistry, but then the nucularly bits are way beyond me except that it's still fusion.

      Wow, a Lithium powered sun, that's pretty cool. :-P

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    3. Re:Fission? by kenwd0elq · · Score: 1

      In fact, the fusion of anything that produces an element heavier than iron will extract energy from the star's core, hastening its collapse.

    4. Re:Fission? by Neil+Boekend · · Score: 1

      Wow, a Lithium powered sun, that's pretty cool. :-P

      It sure as hell wouldn't be depressed.

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    5. Re:Fission? by Anonymous Coward · · Score: 0

      The energy doesn't need to be released for there to be fusion. If you get enough iron together to start a gravitational collapse, you'll get a temporary all-iron star. It will use its gravitational energy to sustain fusion. Of course this won't last very long (minutes or hours maybe?).

  21. Found it! by Anonymous Coward · · Score: 0

    Finally, a solution to the "dark matter" problem - stars that have collapsed into a ball of metal (that doesn't radiate vast amounts of energy any more) are the "dark matter" we've been looking for.

    1. Re:Found it! by Anonymous Coward · · Score: 0

      I suspect that this post is a bit tongue-in-cheek, but I'll clear things up lest anyone take this seriously.

      Dark matter isn't just "dark" -- it's invisible. It doesn't interact with light at all. Doesn't emit it, doesn't reflect it, doesn't absorb it. That means that dark matter particles are probably something like neutrinos, which interact so weakly with the electromagnetic force that they can essentially phase right through regular matter. In fact, it is possible that slow-moving neutrinos account for some dark matter. (It's unlikely that neutrinos make up the bulk of dark matter because they are nearly massless.)

      We know that dark matter is invisible and not just "dark" because there are huge halos of it around every galaxy. Astrophysicists use the gravity of these dark matter halos to account for the fact that stars on the outermost edge of a galaxy revolve just as quickly as stars near the center. Even if the halos were composed entirely of black metal stars, the blackness of the halo would block out light from the galaxy. Imagine if Saturn's rings were black: We'd still see them because of the shadow that they'd cast on the planet's surface. This is the same idea.

      Contrast this with black holes, which are actually black. But they are also ridiculously tiny on an astronomical scale, with event horizons that are usually planet-sized. Dark matter halos, on the other hand, are galaxy-sized, and if they were sitting around casting shadows, someone would definitely have spotted one by now.

    2. Re:Found it! by Anonymous Coward · · Score: 0

      Dark matter isn't just "dark" -- it's invisible. It doesn't interact with light at all.

      This isn't certain at all, and it is possible that dark matter still weakly interacts with electromagnetism. Some suggests still involve particles that have decay paths involving photons, and some suggest they can still interact enough to directly cause Cerenkov radiation, which is why there are detectors looking for both (in addition to indirect photons and Cerenkov radiation production). Current astronomical observations greatly limit how much dark matter can interact with light, but not eliminate it. And measurements suggesting it can't be baryonic also limit how much it could be just normal junk floating around (there is still a lot of missing baryonic matter from same CMB predictions too).

  22. Such as a "Death Star" perhaps? by Khopesh · · Score: 1

    Let's not confuse extreme metallicity (the rare star containing nearly zero hydrogen or helium) with an all-metal body.

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  23. And we'll name the first one we find Black Sabbath by Zenin · · Score: 3

    Unless it's made of a light metal...then we'll name it Warrant.

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  24. Solar Accretion by Anonymous Coward · · Score: 0

    Our Sun is very high in metallicity. Consider the fact that it has a spectrographic profile of a solid instead of a gas. In addition, surface features are persistent and lots of iron emissions are present. Someday the textbooks will be updated and we will be able to recreate fusion in a cheap tabletop device. Until then we will have to deal with the ignorance built up over hundred of years of dogma (Sun is helium/hydrogen). Cold fusion science (LENR) is just the beginning of an awesome world of possibility.

  25. Implication for stellar clusters by arcctgx · · Score: 2

    If I'm reading TFA correctly, it basically means that stars formed from one molecular cloud have very different metallicities - anywhere between the mean metallicity of the molecular cloud and the "purely metal" extreme. If this is actually true, there may be far reaching implications for the research of stellar clusters. One of the basic assumptions in this field is that all cluster stars created from a given molecular cloud have very similar chemical compositions.

  26. That's not a... by Anonymous Coward · · Score: 0

    Moon/Star. DeathStar!!

  27. What kind of planet would a metal star make? by Y.A.A.P. · · Score: 1

    Cybertron

  28. Not the Usual Definition of Metal by kenwd0elq · · Score: 4, Informative

    In astrophysics, the term "metal" normally applies to any element heavier than lithium. Carbon, silicon, even gasses like oxygen and nitrogen, are "metals". We're not talking about star remnants that are primarily iron or lead or uranium. Gold would be right out.

    1. Re:Not the Usual Definition of Metal by ccanucs · · Score: 2

      So - no gold star... Oh well :-)

    2. Re:Not the Usual Definition of Metal by NoNonAlphaCharsHere · · Score: 1

      Well, I LOLed. Sorry, no mod points.

  29. does it fuse? by Anonymous Coward · · Score: 0

    My embarrasing-level understanding wonders: the stuff heavier than iron want to come apart, not come together. Does the star, uh, work?

    1. Re:does it fuse? by CaptainDork · · Score: 2

      The iron doesn't "want" to come apart, and doesn't.

      The star is a fine balance of gravitational attraction that compresses of all its parts to the point of fusion at the center, and the expansion of the star as the pressure of fusing energy at the center wants to expand the star.

      At first, hydrogen is converted to helium and that process is so energy-rich that the star doesn't struggle much to hold off the collapsing effect of gravity.

      As other elements are converted from one to the other, the fusion process is less efficient in producing energy and the star struggles even more to fight off gravity and becomes more dense

      At the last stage of the star's life, when it produces iron, the star hits a brick wall. Fusion is not robust enough to convert iron into the next element.

      What happens next is amazing because gravity finally overcomes the expanding process of fusion.

      The star collapses very quickly, and THAT enormous pressure jams particles together so violently that heavier, more complex elements than iron are made through fission, and at the same time, the star is exploding.

      The iron atoms do not come apart. They ride the shock wave.

      --
      It little behooves the best of us to comment on the rest of us.
  30. Saw the headline by Anonymous Coward · · Score: 0

    And I thought if any astrophysicist discovered stars that were totally metal, it would be this guy: http://youtu.be/uVj9DISZ3-s

  31. Pinball by CanEHdian · · Score: 1

    See, there is a God! The Universe is a gigantic Pinball machine and He has just unlocked a Super Multi-ball!

    --
    When the copyright term is "forever minus a day", live every day like it's the last.
  32. That's totally metal... by Anonymous Coward · · Score: 0

    This made me think of Nathan Explosion describing stars...

  33. We have yet to find a star with this spectrum by earthforce_1 · · Score: 3, Interesting

    And we have been studying stellar spectra for a century now. The must be much rarer than 1 in 10,000 or we would have already found one. They must be exceedingly rare.

    --
    My rights don't need management.
    1. Re:We have yet to find a star with this spectrum by Anonymous Coward · · Score: 2, Interesting

      How would you spot them? The stellar spectra you mention are visible because of all the energy that a non-metallic star can generate through fusion. But metal stars don't have that energy available. They'll be dim, which affects the distance at which we can spot them. The lack of light also complicates our ability to determine their spectra. So the fraction of metal stars amongst the stars with a known spectrum will be even lower than that 1:10000.

  34. Some metal stars aren't far away by Anonymous Coward · · Score: 0

    Some nearby metal stars.

  35. Planets rotate around stars by billstewart · · Score: 1

    It's not a planet unless it's a planet. And if it's generating radiation through fusion, it's a star of some kind.

    --

    Bill Stewart
    New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
  36. myNOemail@isSPAMpublic.com by globaljustin · · Score: 1

    so, i'm supposed to worry about 1337 h4xxxx0rz who have my public email, which I made public, right in my profile?

    --
    Thank you Dave Raggett
  37. Also huge metal planets? by Anonymous Coward · · Score: 0

    Recently we found a mega-earth, a rocky planet that was much larger than thought possible for rocky planets. Could this be formed by a similar phenomenon that creates metallic stars?

  38. Metal as in... by Anonymous Coward · · Score: 0

    We talking of metal as in Iron or Metal as in devil worshipping?

  39. Iain M Banks by Anonymous Coward · · Score: 0

    It's at times like this one feels the loss of Iain Banks all the more acutely. I would have really looked forward to finding out how he would've worked metal stars into the next Culture novel.

  40. Perfect match... by Anonymous Coward · · Score: 0

    ..for a totally metal astronomer: https://www.google.com/search?q=jay+farihi+astronomer

  41. Stellar Alchemist by valley · · Score: 1

    My heart's an iron fist ... http://www.youtube.com/watch?v...

  42. The first metal star was Hendrix. by Anonymous Coward · · Score: 0

    Good name for a star, isn't it? "And this right here is the Hendrix Star, blue metal giant headed toward supernova."

  43. Re:Metal Stars by cusco · · Score: 1

    Leave your hearing aids at home . . .

    --
    "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
  44. could by Anonymous Coward · · Score: 0

    could we have started our universe from a supernova instead of the "bigbang" ? it seems both have a single point of origin wich means we are made of recycled material?

  45. Totally Metal stars? ROCK! by BitwizeGHC · · Score: 1

    I expected the astrophysicist to be Queen guitarist Brian May...

    --
    N4st0r, trixx0r h0bb1tz0rz! Th3y st0l3 0ur pr3c10uzz!
  46. Of course they are... by Anonymous Coward · · Score: 0

    ...they are called "Death Stars".
    We have known this for at least 30 years.

  47. Re:Metal Stars by grub · · Score: 1

    It's crazy but my hearing is excellent at 48. That's after ~30+ years of blowing them out with Lemmy and other noise. I'm sure one day damage will just arise.

    --
    Trolling is a art,
  48. "...push heavy particles into the calmer space..." by Anonymous Coward · · Score: 0

    Like a cosmic Dyson vacuum cleaner.

    We are all just, lint.