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Astronomers Discover the Coolest Known Sub-Stellar Body

Posted by Soulskill on from the miles-davis's-home-planet dept.

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."

5 of 60 comments (clear)

  1. What's the bigger news here? by T+Murphy · · Score: 2, Interesting

    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?

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  2. These should be common by Toonol · · Score: 2, Interesting

    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.

    1. Re:These should be common by clyde_cadiddlehopper · · 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?

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  3. Re:Coolest? by John+Hasler · · Score: 3, Interesting

    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.

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  4. update WP by bcrowell · · Score: 2, Interesting

    Sounds like it's time for someone with the relevant expertise to update this: http://en.wikipedia.org/wiki/Brown_dwarf#Spectral_class_Y

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