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A 13.2Billion year old star just 186 Lyrs from earth

  1. Jun 6, 2013 #1
  2. jcsd
  3. Jun 6, 2013 #2

    Bandersnatch

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    The article mentions explicitly that this is not a population III star, due to the measured abundance of metals.
     
  4. Jun 6, 2013 #3

    Chronos

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    Population III stars are expected to be very short lived, so its not big surprise we haven't seen any. The age of a star has little to do with redshift. Stars at high redshift are limited in age to that of the universe at that age, so a star with a redshift of 2 could not be more than about 3 billion years of age given the universe itself was only about 3.3 billion years old when those photons left that star. Hence, it is unsurprising some of the oldest stars in the universe are relatively nearby. A low mass star like a red dwarf is capable of 'living' much longer than the age of the universe. A star like the sun has a main sequence life expectancy of around 9 billion years.
     
  5. Jun 8, 2013 #4
    Just to clarify, I did not know the definitions of the various star population classes. My recollection was that the first stars were very short lived hence my surprise to find that one as old as this still existed in our own back yard. I think this article says that this old star HD 140283, is a population II star.
     
  6. Jun 8, 2013 #5

    Chronos

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    Given its relatively high velocity, HD 140283 could be a star ejected by a nearby low metallicity dwarf galaxy.
     
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