Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
For the out-of-band Slashdot experience (mostly headlines), follow us on Twitter, or Facebook. ×

The Sun Had Sisters 155 155

[TheBORG] writes to mention a Space.com article about the Sun's departed solar siblings. Our own medium-sized yellow star was far from alone when it was formed, with hundreds of fellow solar bodies and a supernova to keep it company. From the article: "The evidence for the solar sisters was found in daughters--such as decayed particles from radioactive isotopes of iron--trapped in meteorites, which can be studied as fossil remnants of the early solar system. These daughter species allowed Looney and his colleagues to discern that a supernova with the mass of about 20 suns exploded relatively near the early Sun when it formed 4.6 billion years ago; and where there are supernovas or any massive star, you also see hundreds to thousands of sun-like stars, he said. The cluster of thousands of stars dispersed billions of years ago due to a lack of gravitational pull, Looney said, leaving the sisters 'lost in space' and our Sun looking like an only child ever since, he said."
This discussion has been archived. No new comments can be posted.

The Sun Had Sisters

Comments Filter:
  • They were doing the Nutron Dance....woooohooo...
  • by Kelson (129150) * on Tuesday October 24, 2006 @12:56PM (#16562272) Homepage Journal
    ...but an appropriate name for an astrophysicist.
  • Pah! (Score:1, Funny)

    by Anonymous Coward
    Pah, evidence. Faith and internal revelation is a much more powerful "way of knowing." Look at me! I'm an epistomologist!
  • A guy named Looney is trying to tell us the Sun had sisters.
  • Sisters? (Score:5, Funny)

    by MANYplaces84 (853635) on Tuesday October 24, 2006 @12:59PM (#16562352) Homepage
    I bet they were hot!
  • by pandrijeczko (588093) on Tuesday October 24, 2006 @01:04PM (#16562452)
    ...which would make them *THE DAUGHTERS*.

    HA! The sun would have to get up *PRETTY EARLY IN THE MORNING* to catch *ME* out"!!!

    Oh wait...

  • So a supernova of 20 suns equivalent managed to explode and leave behind thousands of sun-like stars?

    Apparently conservation of mass laws were different back then.
    • No, the areas wher you find the massive and super massive starts that can go nova usually have lots of sun sized stars also. The solar system was bombarded by the debris from a nearby super nova early in its life, ergo it was part of a stellar cluster.
      • Danger. Do not post while you have a burger in your hand and the music blaring otherwise you may spell as poorly as I did in the previous post.
    • by dlenmn (145080)
      TFA said "a supernova with the mass of about 20 suns exploded relatively near the early Sun when it formed 4.6 billion years ago." It did not say that the stars came from the remains of the supernova.
    • Re:Huh? (Score:5, Insightful)

      by arth1 (260657) on Tuesday October 24, 2006 @01:26PM (#16562908) Homepage Journal
      Another thing I find odd is the timeline. The universe is around 14 billion years old, and the solar system around 5-6 billion years old. The heavy elements we find in the solar system must have come from supernovas or similar, but type II supernovas take an awful long time to mature, so there can't have been several generations of them; the universe is just too young.
      I'm surprised that the Universe is as developed as it is, being this young.

      Regards,
      --
      *Art
      • Re:Huh? (Score:5, Interesting)

        by Dadoo (899435) on Tuesday October 24, 2006 @01:59PM (#16563522) Journal
        type II supernovas take an awful long time to mature

        I'm pretty sure that's not true. Remember: the larger the star, the shorter its life. Really large stars have lifetimes of just a few tens of millions of years, while red dwarfs can live trillions, according to current theory. While a 20 solar mass star isn't that big, I imagine it still didn't last long.
      • by booch (4157)
        I'm surprised that the Universe is as developed as it is, being this young.

        Er, that sounds a lot like the Anthropomorphic Principal [wikipedia.org] could explain that.
        • by Gropo (445879)
          There I was, expecting some smartassed 'principal' that basically claims 'the moment you anthropomorphise (IE apply human characteristics) the clockwork of the Universe, you're officially wrong' rofl

          Weirdest typo I've seen all year.
      • by bobetov (448774)
        I'm surprised that the Universe is as developed as it is, being this young.
        Officer, I swear she looked 18!
      • Re:Huh? (Score:5, Informative)

        by helioquake (841463) on Tuesday October 24, 2006 @02:35PM (#16564304) Journal
        Dadoo is correct. A very massive star has to have a hotter core at its center in order to support its heavier stellar mass (the hotter the gas, the higher the gas pressure, and hence the more effective to support its own weight in order not to collapse into a singularity, i.e., a blackhole). And the rate of nuclear reaction is often proportional to a higher power of Temperature at the core. That means the hotter the core is, the faster it is to synthesize heavier elements from proton to Helium.

        As the same star evolves, it depletes hydrogen (proton) soon at the core. But because the star is still massive, it enables to burn helium, then carbon, oxygen, nitrogen, and eventually it starts burning more heavier elements via nuclear processing (til iron -- Fe -- which cannot be burned to generate nuclear energy).

        This heavier element synthesis is accelerated by high temperature and pressure (basically) at the core of a star. For a very massive star (Mass ~ 100 sun) it lives only about a few million years before it begins to show the sign of aging (heavier metallic elements in its atmosphere). And when these stars die, their explosions would disperse these heavier elements throughout its neighboring space (also upon explosion, an ample flux of neutrons would bombard other atoms and eventually the atoms trap the neutrons to form heavier elements than Fe; Strontium, uranium, plutonium and gold are good examples of such process).

        In a small star like the Sun, the synthesis process takes place very slowly (in the time scale of a few billion years). So it's only natural that astrophysicits think today that there must have been a lot of very massive stars formed in the early days of the Universe to explain its metallicity level seen today.
    • Re:Huh? (Score:5, Informative)

      by cruachan (113813) on Tuesday October 24, 2006 @01:27PM (#16562926)
      No, as I understand the theory (and IANAA - well except an occassional amateur one) if a supernova explodes in or near a gas cloud the shockwave initiates star formation.
    • Re: (Score:2, Informative)

      by AlecC (512609)
      No. The shockwave from the supernova produced localized density increases in a nearby or surrounding gas cloud. These density increases pushed the local gravitational field over the level at which the gas begins to accrete into what will eventually become a star. Such shock waves are the main cause of starts being formed, and the reason why there are "star nurseries" - volumes of space in which a large number of new stars are being born.
    • I'm surprised that the Universe is as developed as it is, being this young.
      It's all the hormones in the beef that do that, I hear.

      At any rate, it's best not to take notice, as the world seems to be on max pedophile alert.
    • So a supernova of 20 suns equivalent managed to explode and leave behind thousands of sun-like stars? Apparently conservation of mass laws were different back then.

      conservation of mass is not the issue. The sun-like stars were not made from the mass of the exploded star. The explosion caused a shock wave in the interstaller gas. The shock wave is a density variation that trigged gravatational colapse at hundrds of points in the cloud. Some of those points became stars.

    • "So a supernova of 20 suns equivalent managed to explode and leave behind thousands of sun-like stars? Apparently conservation of mass laws were different back then."

      Apparently you had trouble comprehending TFA, assuming you read it in the first place.
  • This is pure crap I'm spittin out here, but I suppose anything is possible...

    So it's slightly possible that George Lucas wasn't lying and the whole galactic-terran-empire "long-long ago" thing really happened?
    In all seriousness though (well, half seriousness), suppose this would mean that Earth IS that bunch of humans huddled around a burning-trash-can of a black-hole?
    • by El Torico (732160)
      In all seriousness though (well, half seriousness), suppose this would mean that Earth IS that bunch of humans huddled around a burning-trash-can of a black-hole?

      I think it the exact opposite; the Sol system is the stellar equivalent of the Riviera. Too bad we keep littering up the place.

  • by 955301 (209856) on Tuesday October 24, 2006 @01:12PM (#16562602) Journal
    Let me see if I have this clear now. We are mold forming upon the scum on top of a molten pile of rock swinging around a hot piece of miniscule debris left over from a single speck exploding on the outskirts of a tiny disk floating in a vast space full of other tiny disks and whatnot? And the going theories include one where this vast space is only one of an infinite number of vast spaces?

    Put's watching my diet in perpective, that's for certain.
    • Well at least we're huge on a molecular level :)

      Puny electrons!
    • Re: (Score:2, Funny)

      by TheForgotton (995762)
      Have you ever considered becoming an organ donor?
      • by 955301 (209856)
        Not with the human races current track record of ethics and morals and the prospects of having my organ sold by some corporation for an extreme amount of money.

        Have you considered shopping around for a new sense of humour?
        • by RsG (809189)
          You missed the Monty Python reference in the parent post. What you said is quite a bit like what John Cleese sang in The Meaning of Life, during the "organ donor" sketch. Turn in your geek card buddy :-)
          • by 955301 (209856)

            Curses! And I just got this thing after buying a new macbook because of the bash terminal & bsd backend. Wow, I was so focused on what appeared to be a troll-like response that I missed that.

            Thanks for the heads up
  • by corbettw (214229) <corbettw AT yahoo DOT com> on Tuesday October 24, 2006 @01:15PM (#16562646) Journal
    So the claim is that hundreds, maybe thousands, of sun-like stars were in close proximity to each other, but they didn't generate enough gravity to stay in the same neighborhood? How does that make any kind of sense?
    • by pclminion (145572) on Tuesday October 24, 2006 @01:20PM (#16562786)

      So the claim is that hundreds, maybe thousands, of sun-like stars were in close proximity to each other, but they didn't generate enough gravity to stay in the same neighborhood? How does that make any kind of sense?

      Allow me to introduce my good friend, Kinetic Energy.

      • Aye, but where's the supernova remnant itself? The rapidly-rotating neutron star with the nasty high-energy pulsar radiation? It was at the center of the explosion, so it had an initial kinetic energy of nearly zero. It should still be in the stellar neighborhood.

        Unless the argument here is that the Sun itself was blown away from the site of the supernova...
        • by pclminion (145572)

          Aye, but where's the supernova remnant itself? The rapidly-rotating neutron star with the nasty high-energy pulsar radiation? It was at the center of the explosion, so it had an initial kinetic energy of nearly zero.

          A massive, rapidly rotating object has a kinetic energy of nearly zero? What professor did you hear this from, he/she needs a beatdown.

          A few things that commonly confuse people: 1) Kinetic energy is NOT conserved. TOTAL ENERGY is. 2) Momentum and kinetic energy are NOT THE SAME THING. 3) A

          • I mean translational kinetic energy, fergawdsake. Good grief, must we wallow in Dictionopolis definitioneering when there's interesting astrophysics to ponder?
            • by pclminion (145572)

              I mean translational kinetic energy, fergawdsake. Good grief, must we wallow in Dictionopolis definitioneering when there's interesting astrophysics to ponder?

              There is a huge translational kinetic energy involved -- the translation of each individual particle in the neutron star as it rotates. The body viewed as a whole has no translational energy. The sum of the translational energies of all the particles is equal to the rotational K.E. of the body. This energy can't just disappear when the body breaks

        • by wanerious (712877)
          Aye, but where's the supernova remnant itself? The rapidly-rotating neutron star with the nasty high-energy pulsar radiation? It was at the center of the explosion, so it had an initial kinetic energy of nearly zero. It should still be in the stellar neighborhood.

          It's becoming more common now to see pulsars and neutron stars with really high peculiar velocities away from the site of the explosion. Inhomogeneous conditions during the collapse and explosion can propel the remnant away from the center of

      • Re: (Score:3, Funny)

        by vtcodger (957785)
        No, you don't understand. The cluster was a bit sloppy about its financial mangement, maxed out the credit cards took out some unfortunate adjustable rate loans and eventually its financial situation became untenable. The banks grabbed the only remaining asset -- the gravity.

        So here we are, orphaned, adrift and alone. An object lesson for all to observe ...

    • by 2short (466733)
      It does not make sense if you just read the summary article, and from that conclude something like: There were a whole BUNCH of stars, and they were like, WAY close together, which would mean a BUTLOAD of gravity, so even though there was an explosion, or they were moving real fast or something, I totaly don't get how they could get away.

      I would speculate that it does make sense if you actually do the math, as astrophysicists are wont to do.

      Sorry, but it's awfully typical: Slashdot reports
  • Dearly Departed (Score:4, Interesting)

    by Doc Ruby (173196) on Tuesday October 24, 2006 @01:15PM (#16562662) Homepage Journal
    "The cluster of thousands of stars dispersed billions of years ago due to a lack of gravitational pull, Looney said"

    How does that work? These stars are the gravitational pull, local "depressions" in the spacetime fabric that bend space around them towards themselves. Which is gravitational pull. Which must be overcome by some other force, either other gravitational pull from some other, larger/closer mass(es), or momentum from a kinetic event like a collision. Maybe the exploding supernova knocked them out of the area. Maybe, if it was big enough, its departing mass would have not only knocked the stars away, but pulled them away, overcoming their mutual gravitational attraction through greater departing, but still attractive, mass.

    But something did. That's the biggest missing factor in this whole proposed scenario, in Robin Lloyd's Space.com story about it at least, that it needs to hold it together. Theories fall apart because of a lack of gravity, star clusters not so much.
    • Re: (Score:3, Informative)

      by Chris Burke (6130)
      Star clusters fall apart from lack of sufficient gravitational attraction all the time. This shouldn't be surprising. Just because some stars are rotating around each other for a while doesn't mean the orbits are stable.

      The article doesn't say exactly, but there's some easy inferences. We were part of a star cluster. There was a large star in the cluster, providing a large amount of gravitational attraction. That star then went nova, shedding a large portion of its mass. Ta-da, there is no longer enou
      • Re: (Score:3, Insightful)

        by Doc Ruby (173196)
        Or it was something else. You can't just infer the scenario you describe was the one. The one I described, collision/dragging interaction with the supernova mass, is just as plausible. The ambiguity is at the center of "what happened?", and there are many mutually exclusive and combinatory possiblities.
        • Re: (Score:3, Interesting)

          by Chris Burke (6130)
          Or it was something else. You can't just infer the scenario you describe was the one.

          Yeah, or it was something else. There are about a billion things that could have prevented the star cluster from being stable. I was merely presenting the simplest and most obvious one, just as an example. Your post implied that it seemed implausible that a star cluster could fly apart, and that without this crucial piece of information you refused to believe the conclusion that there was in fact such a cluster -- "Theo
      • by kilonad (157396) *
        Question: What would happen to the Earth's orbit if the sun suddenly turned into a black hole?

        Answer: Virtually nothing. Why nothing? Because the mass is the same, and it's got the same center of mass. It's therefore equivalent. If a star goes nova, it still has the same center of mass and weighs the same (minus a small fraction of mass being converted into energy during the nova process).

        Just giving you some more stuff to ponder.
        • by Chris Burke (6130)
          If a star goes nova, it still has the same center of mass and weighs the same (minus a small fraction of mass being converted into energy during the nova process).

          A supernova is a star exploding, as in ejecting all or the majority of its mass outward in all directions.

          The math that allows you to treat an object as though it were a point of the same mass at the object's center of mass does not work when you are inside the object (i.e. the expanding sphere of the exploding star's shockwave has passed you). I
          • by kilonad (157396) *
            Ah yes, but we're talking the gravitational pull between stars in a star cluster here, where the stars are a few light years apart.
            • by Chris Burke (6130)
              Ah yes, but we're talking the gravitational pull between stars in a star cluster here, where the stars are a few light years apart.

              I'm not seeing your point. The mass of the exploded star is moving outward at 3% of the speed of light, so in an astronomically insignificant time frame that mass will be outside of the star cluster and thus not contributing to holding it together any more.
    • Re: (Score:3, Interesting)

      by khallow (566160)
      Recall that this cluster would be immersed in the Milky Way and have a cross-section far larger than the Solar System. I imagine that a small weakly linked cluster would have been torn apart by numerous perturbations by massive stars passing through.
    • by jrumney (197329)
      "The cluster of thousands of stars dispersed billions of years ago due to a lack of gravitational pull, Looney said"

      How does that work?

      There was a supernova that was pulling them together. It blew up.

      • by Doc Ruby (173196)
        Yes, and like I said, that mass didn't just disappear. I speculated that the departing mass might have collided with the remaining stars (as it did with the debris from which we're taking the "fingerprints" of the event), and even dragged along the stars with its continuing gravity.

        Others have speculated that the remaining stars' existing orbits around the now diffuse/moved gravitational center of the now-supernova flung them tangentially as the center of mass moved.

        "It blew up" is a description referring m
  • by blamanj (253811) on Tuesday October 24, 2006 @01:25PM (#16562874)
    A finding like this would lend support to the Nemesis theory [wikipedia.org]. If our sun and any of those sister stars are still in some gravitational cycle, it could help explain the periodic extinctions that seem to occur every 26 million years. [rochester.edu]
    • I remember hearing this theory many years ago (15 or so), but I also remember it being said that measuring perturbations over several years would validate the theory. I never heard any conclusion, so I've always assumed the Nemesis theory didn't hold water. BTW, IANAAP.
  • by stile99 (1004110) on Tuesday October 24, 2006 @01:25PM (#16562878)
    A scientist named Twoney is publishing an article in the Astrophysical Journal proposing that a supernova billions of years ago would have resulted in the presence of only one little lonely star in this sector of the galaxy, with the nearest neighbor over four light-years away. "Imagine what a lonely, cold place our solar system would be had this horrible event happened," said Terry Twoney. "Why, our solar system would be so small that life might be viable on just one planet, and Pluto would be so small and cold there would be debates regarding if it even counted as a planet!"
  • by dantheman82 (765429) on Tuesday October 24, 2006 @01:31PM (#16562986) Homepage
    Aren't they Solaris [sun.com], and Coffee Beans [sun.com], the N1 Star [sun.com], and StarSuite [sun.com], as well as GSun [gsun.com] and iSun [isun.com]?
  • Sometimes Sun gets the market share and its siblings vanish into obscurity. Or Sun loses marketshare and DOS or Windows become the star of the show and Sun fades into obscurity. Nothing new. Happens all the time.
  • * solaris
    * sparc
    * java
    * staroffice

    and the out-of-favor niece: linux
  • of a Galactic Porno? I mean, the thing exploded all over the Sun and her Sisters... No wonder they ran away.
  • Can't be (Score:2, Funny)

    If there used to be more suns in the sky, you'd think it would have been mentioned in the bible. Hmmm . . . ?
  • by Colgate2003 (735182) on Tuesday October 24, 2006 @02:18PM (#16563930) Homepage
    I'm working on covering this for the Museum of Science, Boston on our podcast [mos.org]. I tracked down a PDF [arxiv.org] of the actual paper, if anyone is interested.
  • I'd like to make the point that this scenario is what we expected from observing other stars and clusters.

    Stars start forming when giant molecular clouds are compressed, typically by the mass density wave of a spiral arm. This creates a star-forming region, where many thousands of stars will be formed in close proximity. Because the gas is able to efficiently shed kinetic energy (transforming it into heat), the stars have low velocities relative to each other, so are gravitationally bound in an "open cluste
  • thankyou, thankyou, I'll be here all week
  • I mean, you can't pick it up and turn it over.

    A couple of more serious questions:

    Surely if a supernova was that close it would be the event that started the formation of the sun, rather than happening after its formation.

    What's the effect of the outgassing (explosion) on the proper motion of the created stars? What percentage escape the gravitational field of the embedded neutron star?

  • I am know expert but aren't all the element cook up in stars and then disperse by either solar wind or supernovae. We have a pretty good selection of elements here on earth. So much much so that we were able to identify 92 natural elements. 36 of which can only be formed in the explosion of a supernova. Isn't likely that those elements were formed in nearby stars with a close proximity to our sun given the fact that inverse square relationship to particles dispersion and our solar system has rocky planets.
  • I'm confused. Were this SparcStations?

    MjM

news: gotcha

Working...