How can a star in the Milkyway be nearly as old as the universe?

  1. A star by the name of HE-1523-0901 is a star only about half a billion years younger than the universe. I understand that the universe expanded faster than light after the big-bang, but I am having a hard time understanding how one star from this time period may have wound up in the Milkyway. It seems improbable.
    http://arxiv.org/abs/astro-ph/0703414
     
  2. jcsd
  3. phinds

    phinds 9,052
    Gold Member

    Since the star is about the same age as the milky way, I don't see the problem.
     
  4. Bill_K

    Bill_K 4,159
    Science Advisor

    It's unusual for an individual star to live that long. The very oldest stars are metal poor, and so it's doubly remarkable that this star has enough U and Th to make an accurate determination of its age possible.
     
  5. phinds

    phinds 9,052
    Gold Member

    Good point. I didn't think of it that way, and since the OP didn't give any reason for his puzzlement, it's not clear that he did either.
     
  6. This answered my question perfectly. I found it strange that we would be "lucky" enough to be so close to the origin of the universe. So, though poorly worded, that was my question. As for the thorium and uranium measurements, i did consider that it would be hard for enough to exist to measure correctly, but I don't know enough on dating material in this manner to really offer any real question on it. I supposed that should there be a fault in this type of dating, someone would bring it up as a possible reason behind the age of the star.
     
  7. Chronos

    Chronos 10,060
    Science Advisor
    Gold Member

    I believe 500 million years is enough time for a significant number of first generation stars to form and to go supernova.
     
  8. phinds

    phinds 9,052
    Gold Member

    Keep in mind that "we", if you extend that to mean not just us but our solar system, were NOT created near the temporal beginning of the universe, even though we are in a galaxy that was. Our solar system is less than 5 billion years old.
     
  9. HE-1523-0901 is a Pop II star.
    our Galaxy is thought to have grown by the accretion of surrounding material.
    we have collection of stars called globuler cluster of which there are about 150-200 around our Galaxy.
    these globuler clusters very in age . and is an indication that all the stars in the Galaxy were not all formed at the same time, but rather the galxy also grew by accretion of older matter ..
     
  10. D H

    Staff: Mentor

    You appear to be thinking that the big bang was an explosion in space about some center of the universe. A much better way to look at things: The big bang was an explosion of space, and there is no center of the universe. (Alternatively, every point in the universe can be viewed as the center.)
     
  11. Really interesting, thanks!
     
  12. That helps quite a bit. Thanks. Im new to this arena (studying economics), but i find it interesting, and hopefully i can gain some knowledge through this forum, it is all appreciated.
     
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