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Space Science

Astronomers Discover the Coolest Known Sub-Stellar Body 60

Hugh Pickens writes "Science Daily reports that using the United Kingdom Infrared Telescope (UKIRT) in Hawaii, astronomers have discovered what may be the coolest sub-stellar body ever found outside our own solar system. Too small to be stars and with insufficient mass to maintain hydrogen-burning nuclear fusion reactions in their cores, 'brown dwarfs' have masses smaller than stars but larger than gas giant planets like Jupiter, with an upper limit in between 75 and 80 Jupiter masses. 'This looks like the fourth time in three years that the UKIRT has made a record breaking discovery of the coolest known brown dwarf, with an estimated temperature not far above 200 degrees Celsius,' says Dr. Philip Lucas at the University of Hertfordshire. Due to their low temperature these objects are very faint in visible light, and are detected by their glow at infrared wavelengths. The object known as SDSS1416+13B is in a wide orbit around a somewhat brighter and warmer brown dwarf, SDSS1416+13A, and the pair is located between 15 and 50 light years from the solar system, which is quite close in astronomical terms."
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Astronomers Discover the Coolest Known Sub-Stellar Body

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  • I'm sure there is a joke in here somewhere involving aliens and mood lighting...
  • But I'm still the awesomest sub-stellar body.

    (Puts on shades.)

    Yeah.

  • Brown dwarfs stars are cooler than some of the (exo)planets found already?
    • I was thinking of this, too... Don't planets and other smaller bodies count as sub-stellar bodies ?
      • Re:Coolest? (Score:4, Interesting)

        by John Hasler ( 414242 ) on Saturday January 30, 2010 @02:16PM (#30964538) Homepage

        I think that by "sub-stellar body" they mean something not orbiting a star.

        BTW as most of the exoplanets found so far orbit very close to their stars and so are rather hot ("hot jupiters") it is likely that this thing is cooler than most of them.

  • by Anonymous Coward on Saturday January 30, 2010 @01:04PM (#30963930)
    That's "African-American little person".
  • by T Murphy ( 1054674 ) on Saturday January 30, 2010 @01:30PM (#30964194) Journal
    Given brown dwarfs generally have no heat source, they cool quickly and we expect there to be cold ones out there. Is the bigger news the fact that we could detect this cool object, or the information gained by finding this brown dwarf?
  • So... (Score:3, Funny)

    by drej ( 1663541 ) on Saturday January 30, 2010 @01:56PM (#30964394)
    So Fonzie is now a body in outer space?
  • So? (Score:1, Funny)

    by Anonymous Coward

    Shouldn't they be looking for the hottest stellar body, if you know what I mean?

  • by Toonol ( 1057698 ) on Saturday January 30, 2010 @02:06PM (#30964464)
    I know we can't make too many assumptions, but I think common sense would indicate there's trillions of these things floating out there. I would think there's more of these in the galaxy than stars, if you just continue the mass/frequency curve past the point that fusion ignites.
    • Re: (Score:2, Interesting)

      What percentage of dark matter would these account for? Or is the mass of these sub-stellar objects already included in gravitational models of galaxies?
      • Re: (Score:3, Informative)

        by Tim C ( 15259 )

        0; dark matter isn't normal matter that we just can't see, it's an entirely different form of matter (at least according to the theory).

        • Thank you. I should've known the distinction between baryonic dark matter [wikipedia.org] (not-glowing-ordinary-proton-and-neutron-stuff) and the spooky kind that doesn't interact with light.
        • by Urkki ( 668283 )

          0; dark matter isn't normal matter that we just can't see, it's an entirely different form of matter (at least according to the theory).

          Actually "dark matter" refers to an matter we don't see. So brown dwarfs etc. (that are sufficiently far to be undetectable) qualify as dark matter. But current understanding is, that baryonic dark matter (ie. brown dwarfs and stuff) is tiny fraction of non-baryonic dark matter, which is what you're talking about above.

    • Re: (Score:3, Informative)

      by Eudial ( 590661 )

      I know we can't make too many assumptions, but I think common sense would indicate there's trillions of these things floating out there. I would think there's more of these in the galaxy than stars, if you just continue the mass/frequency curve past the point that fusion ignites.

      That's a pretty common astrophysical assumption though, that the universe is homogenous and isotropic [wikipedia.org]. Or in simpler words, our corner of space is not significantly different from any other corner of space. So if we find these guys floating around in space, similar objects will likely float around elsewhere as well.

    • by hldn ( 1085833 )

      double facepalm to those that thought 'sub-stellar body' meant it was kinda tubby.

  • I mean if Jupiter’s surface temperature is below 200 degrees Celsius (and i bet it is), and since it’s also a brown dwarf (even with nuclear reactions going on in its core), shouldn’t it be even cooler?
    Also, what about Saturn, Neptune and Uranus, who just as much count as brown dwarfs, since they are mainly built like a star.

    • Re: (Score:1, Flamebait)

      by John Hasler ( 414242 )

      > I mean if Jupiter's surface temperature is below 200 degrees Celsius (and i
      > bet it is)...

      165K (defining "surface" as "1 bar pressure level")

      > ...and since it's also a brown dwarf...

      No it isn't.

    • Yeah but all of those object are not "outside our own solar system". If they were, they would be very hard to detect.

    • by osu-neko ( 2604 )

      I mean if Jupiter’s surface temperature is below 200 degrees Celsius (and i bet it is), and since it’s also a brown dwarf...

      Jupiter is not a brown dwarf. It orbits the Sun.

      Also, what about Saturn, Neptune and Uranus, who just as much count as brown dwarfs,

      Correct, insofar as "just as much count" correctly notes that none of these bodies are brown dwarves.

      ... since they are mainly built like a star.

      How something is built does not alone define its astronomical classification. If the Earth orbited a gas giant, it would be a moon rather than a planet. If Titan did not orbit Saturn but orbited the Sun, it would be a planet, not a moon. If Jupiter would flying free through interstellar space with no star to orbit, it would be a brown dwarf. But in fact, i

      • Re: (Score:1, Flamebait)

        by John Hasler ( 414242 )

        > If Jupiter would flying free through interstellar space with no star to
        > orbit, it would be a brown dwarf.

        No it wouldn't.

  • Since it's the coolest known, if Fonzie doesn't already have a sub-stellar body named after him, this one should be it.

  • update WP (Score:3, Interesting)

    by bcrowell ( 177657 ) on Saturday January 30, 2010 @04:31PM (#30965656) Homepage
    Sounds like it's time for someone with the relevant expertise to update this: http://en.wikipedia.org/wiki/Brown_dwarf#Spectral_class_Y [wikipedia.org]
  • Actually there are suspected to be more brown drawfs, failed stars with not enough gas for fusion , in the galaxy than there will be normal stars. If thats so they should be many (tens) brown drawfs within ten light years of us. Brown drawfs of course are so very dim, that its very difficult to spot them at all. But UKIRT is any all sky survey that will take years to complete, and we can expect them to find a lot more brown drawfs.

    ---

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  • :)

  • Posting to remove an erroneous moderation.
  • A system of brown dwarfs (dwarves?) like this must be an awesome sight, although I expect this one is probably too widely separated to be all that spectacular. But the idea of a gas giant/brown dwarf so large it has planets the size of Jupiter as moons is pretty staggering.

Every nonzero finite dimensional inner product space has an orthonormal basis. It makes sense, when you don't think about it.

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