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Astronomers Discover Third-Closest Star System To Earth

Posted by samzenpus on from the howdy-neighbor dept.

The Bad Astronomer writes "Astronomers have found the third-closest star system to the Earth: called WISE 1049-5319, it's a binary brown dwarf system just 6.5 light years away. Brown dwarfs are faint, low mass objects 13 — 75 times the mass of Jupiter, and are so dim they are very difficult to detect. These newly-found nearby objects were seen in observations from 1978 but went unnoticed at the time, but since that date the large apparent motion of the binary made their proximity obvious. Only two star systems are closer: Alpha Centauri (4.3 light years) and Barnard's star (6 light years)."

22 of 151 comments (clear)

  1. These are the starts that are closest to me by Anonymous Coward · · Score: 5, Funny

    Sheldon's going to have to fix his song.

    1. Re:These are the starts that are closest to me by Dr.+Sheldon+Cooper · · Score: 5, Funny

      I most certainly shall not. I don't consider a brown dwarf to be a real star. I generally don't spend time considering topics related to astronomy at all, as it is widely known that astronomy is a field for children or H1B imports with selective mutism and a penchant for broadway musicals.

      To put it in terms you would be more likely to understand, if stars were thespians, a brown dwarf would be on par with Jean Claude Van Damme.

      And before you ask, a thespian is what you normies call an actor.

      --
      Bazinga.
  2. If brown dwarfs can't sustain fusion by mozumder · · Score: 5, Interesting

    then why are they considered stars?

    1. Re:If brown dwarfs can't sustain fusion by MyLongNickName · · Score: 3, Interesting

      I'm not sure why this is modded down. A brown dwarf never achieves sustained fusion and is not considered a full-fledged star, so i am also confused to why it is considered a star system.

      --
      See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
    2. Re:If brown dwarfs can't sustain fusion by skade88 · · Score: 4, Informative

      According to the Brown Dwarf Wiki article "However, for some years now there has been debate concerning what criterion to use for defining the separation between a brown dwarf and a giant planet at very low brown dwarf masses (~13 Jupiter masses).[3] One school of thought is based on formation, and another on interior physics.[3] Dwarfs are categorized by spectral classification, with the major types being M, L, T, and Y.[3] Despite their name, most brown dwarfs would appear magenta to the human eye.[3] Another debate is whether brown dwarfs are required to have experienced fusion at some point in their history. Some planets are known to orbit brown dwarfs: 2M1207b, MOA-2007-BLG-192Lb, and 2MASS J044144b. Brown dwarfs may have fully convective surfaces and interiors, with no chemical differentiation by depth.[4]" http://en.wikipedia.org/wiki/Brown_dwarf

    3. Re:If brown dwarfs can't sustain fusion by MightyYar · · Score: 3, Interesting

      It's subject to some debate. Basically, mostly the differentiation between a gas giant and a small brown dwarf comes down to how it formed and the physics going on inside.

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
    4. Re:If brown dwarfs can't sustain fusion by skade88 · · Score: 4, Funny

      Dwarf planets and stars are sensitive and preferred it if you called them little planets and little stars.

    5. Re:If brown dwarfs can't sustain fusion by jc42 · · Score: 4, Interesting

      I think if it is the center of a planetary system, then it is a star.

      This is a nice example of why you need to be careful in how you define things. With the above definition, our own sun isn't a "star" (most of the time).

      Isaac Newton was one of the people who pointed this out. The objects in our solar system actually orbit the barycenter of the system, the technical name for what is often called the center of mass (or more weirdly, the center of gravity). Because most of the solar system's mass outside the sun is Jupiter, and because Jupiter is far enough away from the sun, the barycenter of the solar system is usually outside the sun. Not far outside, true, but outside the visible "surface" of the sun. It's only inside the sun when most of the other big planets are on the other side from Jupiter.

      So, technically speaking, Earth and the other planets don't actually orbit the sun; they orbit the barycenter, which is (usually) outside the sun. The sun itself also orbits the same barycenter, in a very close orbit. And a few humorous remarks have been made based on the fact that Newton actually demonstrated that the Earth doesn't revolve around the sun.

      We probably need a better definition of the term "star" than "has planets". That also causes a different problem: It's a circular definition, since the common definition of a "planet" includes orbiting a star. So one might decide that Jupiter is a star, and at least its four major moons instantly become planets, which then is used in the definition of "star" to prove that Jupiter is indeed a star.

      There's a lot of humor in the way such terms are being defined by various (mostly non-astronomical) parties. Maybe we should go back to the definition that a star is an astronomical thing that undergoes sustained nuclear fusion. Ya think that'd work?

      (We do have to carefully word it so that the experimental fusion projects in Earthly labs don't qualify as stars. ;-)

      --
      Those who do study history are doomed to stand helplessly by while everyone else repeats it.
  3. And where's the mass of the universe? by sshambar · · Score: 5, Interesting

    Can someone explain to me how discovering the THIRD closes system to ours in 2013 doesn't suggest that all the Dark Matter(tm) that's out there just isn't a mass of brown dwarfs that we can't see, and not a whole new class of matter?

    1. Re:And where's the mass of the universe? by Waffle+Iron · · Score: 4, Informative

      As I recall, it's because the orbital velocities of regular stars in disk-shaped galaxies suggest that dark matter is distributed spherically around the galactic center rather than concentrated in the disk. That implies that unlike brown dwarfs, dark matter interacts neither with normal matter nor itself by any force other than gravity.

    2. Re:And where's the mass of the universe? by Baloroth · · Score: 5, Informative

      Can someone explain to me how discovering the THIRD closes system to ours in 2013 doesn't suggest that all the Dark Matter(tm) that's out there just isn't a mass of brown dwarfs that we can't see, and not a whole new class of matter?

      Because of Big Bang nucleosynthesis. We can know how much baryonic matter ("normal" matter) there is in the universe by certain cosmological observations. Other cosmological observations show there is more matter out there than that (about 5 times more) and therefore it cannot all be brown dwarfs, black holes, or other dark but non-exotic forms of matter.

      --
      "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
    3. Re:And where's the mass of the universe? by myrikhan · · Score: 4, Informative

      IIRC there aren't enough of them and they're too low mass to make up the dark matter. After a bit of searching I found this thesis. It looks like a good introduction to the area.

      http://arxiv.org/pdf/1110.2757

    4. Re:And where's the mass of the universe? by Charliemopps · · Score: 3, Interesting

      Because dark matter isn't dark because it doesn't give off light. It's dark because it doesn't even interact with normal matter in any other way than gravitation. We can see the effects of its mass, but it does not occlude stars behind it, the light and radio waves passes right through as if it didn't exist.

    5. Re:And where's the mass of the universe? by Hentes · · Score: 3, Informative

      The problem with that is if gravitational anomalies indeed are caused by a form of invisible matter, then its mass would have to be far too great to consist of normal matter. There are many forms of possibly invisible matter: compact stars, neutrinos etc but their masses don't add up to even a fraction of the amount needed.

    6. Re:And where's the mass of the universe? by Waffle+Iron · · Score: 4, Informative

      No, it's the same gravity, which affects both normal matter and dark matter the same.

      The difference is that if dark matter interacted by any force other than gravity (such as electromagnetism, etc.), then it would be deflected on encounters with other objects instead of passing right through them. This would eventually cause the dark matter to settle into a disk, like the rest of the stuff in the galaxy. However, it instead seems to remain in its initial spherical distribution to this day.

  4. Re:Proxima Centauri by skade88 · · Score: 4, Funny

    Mod this up or edit the wiki article so Proxima Centauri is 14 light years away...

  5. Re:Can someone explain something to me? by osu-neko · · Score: 4, Insightful

    The premise behind your question is the fallacy of the convertibility of human time and resources, as if we're all interchangeable and equally qualified to participate in any task. Let me put it this way: how much further would we get into understanding the Standard Model if the millions of people playing World of Warcraft would work on that instead?

    Once you already have the world's theoretical physicists working on theoretical physics problems like like, what makes you think people in other fields would make a useful contribution?

    Astronomers look for objects in the sky because they're astronomers. They aren't going to crack problems of theoretical high-energy physics, and they're not in the mood to play WoW 24/7...

    --
    "Convictions are more dangerous enemies of truth than lies."
  6. new dark matter results any day now by peter303 · · Score: 3, Interesting

    That very expensive special detector on the Space Station is reputed to announce interesting results any day now. Detecting certain classes of dark matter was one of its capabilities.

    Congress had to fund a special extra shuttle launch to get this into orbit. Furtmore, the physicists decided to swap in a new set of magnets last minute, postponing it over a year.

  7. Andromeda "collision" is more scary by peter303 · · Score: 3, Insightful

    Andromeda is trillions of times more massive and will "collide" with the Milky Way in two billion years. But they will interpetrate each other like ghosts passing in the night. Odds are unlikely there wont be a single stellar collision among the trillion stars during the Big Merge. The night sky will become rather interesting with multiple stellar bands lighting the sky.

  8. Re:Proxima Centauri by PhotoJim · · Score: 3, Informative

    True, but Proxima Centauri is a part of the Alpha Centauri star system, so that still makes this the third closest star system.

  9. Re:Third closest system? by Anonymous Coward · · Score: 4, Funny

    Debug your code. The index starts at zero.

  10. very interesting by kilodelta · · Score: 3, Interesting

    And I still maintain if we had funded NASA like we funded them in the 1960's and early 1970's we'd be at Alpha Centauri or Barnard's Star by now. But instead we'd prefer to fund military misadventure. However look at the private interest in mining asteroids - that will be cool!