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How do we account for all the elements in the Universe?

  1. Apr 1, 2012 #1
    Hi all,

    New to the forum - first post.

    I've wondered for a while how all the elements were able to be created given the timeline of the universe.

    If the solar system is ~5billion years old and the universe is 14 billion years old that means that all of the elements of the solar system would have been created in ~9 billion years.

    I've read that all of the higher numbered elements (above iron) were created in supernovae and that a star must have a mass 4 or 5 times times the sun in order to become a supernova.

    Further, a star 4 to 5 times the mass of the sun probably has a lifetime of somewhere between 100 million years to 1 billion years.

    Also the milky way, is ~13 billion years old.

    First, how many supernovae would have been needed to create all the elements (in sufficient quantity) to create our solar system (including the sun) (assuming an "average" sized supernova)? Would just one do it? Meaning could one supernova of say 10 solar masses created enough elements to form our solar system and when it exploded in every direction and enough of that material coalesced in to our solar system?

    Second, how many supernovae would be needed to create all the elements in our galaxy? I'm assuming our galaxy started with enough energy and light elements to create stars and start the process of creating heavier elements.

    Lastly, is there any way to determine where our solar system came from? Obviously at least one supernova created all the higher elements found on the Earth so do we know 'where' that supernova was about 6 billion years ago?

    Thanks in advance!
  2. jcsd
  3. Apr 1, 2012 #2
    Hi Cramer,

    The light elements such as hydrogen, helium, lithium, etc. were produced in the nucleosynthesis following the big bang. All of the heavy elements were, as you said, produced in supernovae.

    For the formation and evolution of the solar system, this should be good:

  4. Apr 2, 2012 #3


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    Supernova appear to have been very common in the early universe. Many of these early stars were incredibly massive and probably only lived a handful of million years before detonating, so heavy element abundance is unsurprising. Most of the heavy elements found on earth were probably generated by second and third generation stars.
  5. Apr 2, 2012 #4


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    I thought only pop II would generate the really heavy elements. Pop III would generate only the lighter ones, up to Fe or so. Guess I should get some facts on that.
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