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Space Earth Sun Microsystems

New Evidence That All Stars Are Born In Pairs (phys.org) 90

InfiniteZero shares a report from Phys.Org: Did our sun have a twin when it was born 4.5 billion years ago? Almost certainly yes -- though not an identical twin. And so did every other sun-like star in the universe, according to a new analysis by a theoretical physicist from UC Berkeley and a radio astronomer from the Smithsonian Astrophysical Observatory at Harvard University. The new assertion is based on a radio survey of a giant molecular cloud filled with recently formed stars in the constellation Perseus, and a mathematical model that can explain the Perseus observations only if all sunlike stars are born with a companion. "We ran a series of statistical models to see if we could account for the relative populations of young single stars and binaries of all separations in the Perseus molecular cloud, and the only model that could reproduce the data was one in which all stars form initially as wide (more than 500 astronomical units) binaries," said co-author Steven Stahler, a UC Berkeley research astronomer. "These systems then either shrink or break apart within a million years." The study has been published in April on the arXiv server.
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New Evidence That All Stars Are Born In Pairs

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  • Frost Fernch Pots (Score:5, Interesting)

    by Hognoxious ( 631665 ) on Friday June 16, 2017 @03:09AM (#54631195) Homepage Journal

    Anyone else read it as Paris? I thought it was going to be some bizarre statistical thing drawn from IMDB.

    More coffee needed, I think.

  • by Anonymous Coward

    That raises the question, what happened to ours?

    • by Anonymous Coward

      No, it's incorrect to say that. It begs the question of what happened to the sun's twin.

    • by Anonymous Coward

      The Sun has a twin somewhere. With a goatee.

    • by Kkloe ( 2751395 ) on Friday June 16, 2017 @03:53AM (#54631317)
      It went its own way to form a better planet system, with blackjack and hookers.
    • by Maritz ( 1829006 )
      The sun was probably formed in a cluster with several other stars. They'll be out there in the galaxy somewhere. We might be able to spot one from an isotopic signature.
    • Jupiter. It simply lost mass as the coalesced to the larger of the pair, with some of it becoming the other planets and most falling into what became the sun. It left Jupiter itself too small to ignite.

      Or, of course, their mathematical model could be completely wrong, because the statement that the "only" mathematical model that could explain the data is one where all stars have partners sounds like science-bullshit-fu of the first order. At least they could have the decency to add "of the ones we thought of" or "of the ones we tried". As it is, we're left with proving that the Sun's supposed partner DOESN'T exist, and since it is very difficult to prove that something doesn't exist when it could be "invisible" in any of the countless ways someting can be invisible in space -- too far away, too small, too dark, too much of it made of of dark matter, concealed by invisible fairies, fallen through to the evil companion Universe where everybody is left handed and drinks absinthe and cherry soda cocktails.

      If it is Jupiter, of course, that makes it easy. It isn't lit, so we know its mass is less than 1/10 (less than 0.075 if you want to be picky) the mass of the sun (no overt fusion, the companion isn't a red dwarf or we couldn't possibly miss it). It has cooled enough to be invisible, which probably adds close to another zero -- if it had a mass 1/80th of the Sun or larger , it would probably have a surface temperature still hot enough to see as it would be a brown dwarf and might sustain some nuclear reactions capable of generating heat in addition to still giving off heat as it slowly collapses. So it pretty much has to be smaller than roughly 13 Jupiter masses, making it technically not a star no matter what. Well, what do we find when we look for very large non-brown-dwarf objects nearby? Jupiter! And heck, through Saturn in for good measure! Jupiter has 1/1000 the mass of the sun, large enough that it is probably still losing heat via its own gravitational collapse but not enough to ignite any serious sustained fusion process. If the proto-star split early enough into Jupiter and Saturn (and the rest of the planets) then the Sun simply won the war for material by having a lot more gravity and hence sweeping up most of the dust before it lit and fusion drove the rest of the material away.

      Which leads us to the remaining problem with their model. They're basing their claim on stellar formation in a dense cloud that created an extended star cluster. Perhaps that isn't a completely general starforming environment, and stars that form from smaller clouds tend to win the race for material and blow the starforming dust away on their newborne light before their smaller companions reach "star" size, even brown dwarf size.

      That would explain why a LOT of stars seem to have Jupiter-scale planets (not that our exoplanet search isn't naturally biased towards finding these planets BECAUSE of their size). I'll bet there is an "alternative" model for star formation that would embrace this possibility and still explain the data from their star cluster but no, I'm sure that they have considered EVERY possibility in order to conclude that it is impossible for the sun not to have a star-sized companion, when it simply doesn't, at least not anywhere anyone can see when looking pretty carefully and with good instruments that would be very, very likely to show it up if it was there.

      • Very interesting and insightful comment (if not only b/c I share a deep appreciation and fascination of astronomy/cosmology/astrophysics). Slashdot needs more of these.

    • It hides behind the Sun so we can never see it. That also explains the weird issues with Mercury's orbit.
    • by TWX ( 665546 )

      Well, there is a theory (lowercase "t") that the periodic extinction events seen on Earth strongly correlate with a long-period orbit of something that swoops-in close enough to the Solar System to disturb Kuiper Belt objects, which sends them into the Inner Solar System to crash into the various planets and moons. A Brown Dwarf Star is generally the size of the object expected to cause this where we wouldn't be able to see it in our sky.

    • Jupiter
  • by calken1979 ( 4891209 ) on Friday June 16, 2017 @03:25AM (#54631233)
    I was scratching my head to think of famous French people only to realise I misread the title.
  • Our sun ate its twin. Fitting.
  • Simple question (Score:2, Interesting)

    by Anonymous Coward

    Does the presence of a sibling star and its gravity have an impact on planet formation?

    • It could have, but at least the 500 AU separation should definitely be sufficient for planets in the 1 AU region to be stable orbits if they happen to form under these conditions.
  • by LeMeilleurNeha ( 4988051 ) on Friday June 16, 2017 @03:32AM (#54631257) Homepage
    Astronomers have even searched for a companion to our sun, a star dubbed Nemesis because it was supposed to have kicked an asteroid into Earth’s orbit that collided with our planet and exterminated the dinosaurs. It has never been found.
    • The Nemesis Hypothesis is very interesting because it helps explain the regularity of mass extinctions. Of course, it could just be the regular harvesting of life in our part of the galaxy by Reavers, Eternal Ones, or The Flood.

      • by Anonymous Coward

        The supposed periodicity of mass extinctions every 26 million years has been disproved. Besides, stars can and do move through the solar system from time to time. Yes, they can and do affect Oort Cloud objects in the process. But it's nothing so periodic as Nemesis supposedly is. It's pretty unlikely that Nemesis exists at all.

        • by Anonymous Coward

          Source of that? Have yet to see any scientific article debunking it with facts.

          Besides, if there is a periodic recurrence of meteor showers or any returning celestial event, that wouldn't advocate against Nemesis, rather help prove something's up there we haven't yet detected, messing with our solar system. Could or could not be Nemesis, but certainly no additional proof it doesn't exist.

  • But I am going to eat this with a lot of salt.

  • Paris ? (Score:2, Funny)

    by Anonymous Coward

    I initially read "Paris", and was a bit confused :)
    Camel Case headlines...

  • For example the Superstar Rajnikanth was born in Bangalore, Karnataka, India.
  • While a mathematical model that says stars are born in pairs is interesting. it is NOT evidence of anything...

    Well, it's evidence that that's how the model works, but it's not evidence of anything in the Real World (tm)....

  • No doubt the research was initiated by the theory that all things, even suns, are able to fluidly assume their own gender. In what possible way could a star do this then, other than to be born as two stars that later collapse into a single stellar identity? The question remains however, if the stars as have checked their privelege. #Killallreddwarfs.
    • Bro, if I could be so bold so as to assume your gender, I'd give you all my mod points if I had them. I came to the comments section specifically to see if anyone had anything funny, snarky, sarcastic, or sardonic to say about UC Berkeley as I was genuinely shocked to hear that anything useful comes out of there. Seriously, I thought UC Berkeley was a liberal arts joke school based on their antics.
  • If this phenomenon only lasts a million years - give or take an order of magnitude, then it's nearly absolutely insignificant / irrelevant to the ~4 billion year life cycle that is apparently required for rocky planets to cool and interesting life to evolve.

    It's also only going to be observable in places like the one being studied... they need to find another cloud to confirm the theory with, otherwise it's just a model made to fit a single dataset.

  • The article says this:

    Many stars have companions

    so why does the article's title (and the article here) say all stars are born in pairs.

    Why this may be true for most stars, because most stars are born in stellar nurseries. It doesn't mean there aren't other circumstances where a star can develop on its own.

    Maybe I am over-reacting to a headline, but I want scientific articles to be accurate so people don't just read headlines and assume they understand everything.

  • I would believe "many stars are born as binaries" or even "most stars are born as binaries", but to claim "ALL stars are born as binaries" would require a whole lot more evidence than a computational model.
  • by Jhon ( 241832 ) on Friday June 16, 2017 @11:25AM (#54633275) Homepage Journal

    It got a better deal in an adjacent spiral arm with a red giant.

  • They are born in pairs so whenever the stars get to close to one another they cause an extinction.

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