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Astronomers Find Sun's Twin

mroch writes "Space.com is reporting that astronomers may have found a solar twin -- a star almost exactly like our own Sun. Interesting tidbits from the article include: "The star, 18 Scorpii, sits about 47.5 light-years away in the constellation Scorpio, and has long-been suspected of being Sun-like. [...] The star burns slightly hotter than the Sun, at 5,789 degrees Kelvin compared to 5,777 degrees. It appears to rotate slightly faster than the Sun, taking 23 days to complete a rotation rather than the Sun's 25." It boggles my mind to think that we can measure temperature that exactly from 279,000,000,000,000 miles away, and that they are complaining over a 12-degree difference."

10 of 132 comments (clear)

  1. Measuring temperature at great distance by Frans+Faase · · Score: 5, Informative

    Distance actually does not matter with respect to the method used to measure the temperature, as long as you have enough light, and there is no disturbing medium in between. Both conditions seems to be met.

    1. Re:Measuring temperature at great distance by !the!bad!fish! · · Score: 4, Funny

      ... no disturbing medium ...
      What like this?

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  2. Measuring a star's temperature. by DjReagan · · Score: 4, Informative

    IIRC, the temperature is measured by the colour of the sun. That doesn't change the further away you get, so its just as accurate over long distances as short. However, there is the problem of dopler shift if the stars are moving away/toward each other.

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    "When I grow up, I want to be a weirdo"
    1. Re:Measuring a star's temperature. by Dr.+GeneMachine · · Score: 5, Informative

      Doppler shift should not be a problem, you can always determine the shift rate from the known frequency of certain absorption lines in the spectrum and reference your spectrum to those lines.

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  3. Earth's twin? by eggstasy · · Score: 4, Interesting

    What do we know about that star and its surroundings? Is it likely to have inhabitable planets or is it bathed by lethal radiation from neighboring novas?
    How long before we can actually check these stars for Earth-like planets? Last I heard, we now had the ability to detect planets slightly smaller than Jupiter. Will we find, or even see, an inhabitable planet within a few decades?

  4. Re:They use spectrometry to measure the heat by LittleBigLui · · Score: 5, Funny

    Yeah, there's much difference between a delta of 12 degrees kelvin and 12 degrees celcius. OTOH, you USians (and UKians?) with your funny measurements probably measure temperatures in ounces, feet or hands or something. :)

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    Free as in mason.
  5. Re:They use spectrometry to measure the heat by ottawanker · · Score: 4, Informative

    Actually, 12 a degree difference in Kelvin is the same as a 12 degree difference in Celcius.

    Really, you shouldn't use the word 'degree' with the work 'Kelvin' as in the case used in the Story. It's preferable to write simply 5789 Kelvin.

  6. Re:Degrees Kelvin, not Kelvin by ottawanker · · Score: 5, Informative

    From The U.S. Metric Association

    The kelvin (K) temperature scale is an extension of the degree Celsius scale down to absolute zero, a hypothetical temperature characterized by a complete absence of heat energy. Temperatures on this scale are called kelvins, NOT degrees kelvin, kelvin is not capitalized, and the symbol (capital K) stands alone with no degree symbol. [In 1967 the new official name and symbol for "kelvin" were set by the 13th General Conference on Weights and Measures (CGPM).]

  7. 50 closest, closest matches to the sun by nimblebrain · · Score: 5, Informative

    I like David Nash's list of 50 nearby sunlike stars within 50 light years.

    18 Scorpii is on there, as is the infamous Tau Ceti. 18 Scorpii was one of the four closest matches.

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    Binary geeks can count to 1,023 on their fingers :)
    1. Re:50 closest, closest matches to the sun by Red+Rocket · · Score: 4, Funny


      Binary geeks can count to 1,023 on their fingers :)

      Lots of people do this. Just the other day, a guy in traffic showed me the how he could convert the decimal number 4 into binary. :)

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