Correct me if I'm wrong, but isn't Sol a 3rd generation sun, and that the reason the Earth has many of the various minerals it does is because they were created in the dying stages of a 2nd generation star? If so, then are there any 2nd generation stars near Sol? How long do they have left? Any 4th generation stars lurking about? Anything unusual show up on spectrographic studies of them?

I've never heard the sun refered to as a 2nd generation star. But the generally accepted theroy of star formation in regards to our sun and solar system is this: A giant star supernovaed, spreading heavy elements from its core across space, in time other stars formed from the debris. So as Carl Sagan said "We are made of star stuff."

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I have never heard this term before? could you - or some one esle who knows - explain what you mean? From what you say I am guessing that the sun has lived and died twice before, this being it's third time around the block? Hmmm.....

it reminds me of my uncles old broom - hes very proud of it,it has lasted fourty years - hes' replaced the handle 4 times and the brush head 5 times :wink:

It isn't quite as straightforward as that;
the type of stars whch become supernovas are very short lived, so the matter that makes up a star might be thrown around in a stellar cloud for several 'generations' in a relatively short time, before setting down to become a yellow dwarf like the sun.

Certainly the proportion of heavier elements in stars is increasing as the galaxy and the universe gets older,
but I don't think you can really say that a particular star is purely second generation or third generation.
Some of the bright shortlived stars that have been recently formed might consist of matter which has been inside three or more earlier stars, I should think, but I would gladly defer to someone who really knows.

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Not reading the thread title properly, I though this was about the film Star Trek Generations.

All I know is that it isn't a first generation star because the heavy elements had to come from somewhere.

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Not quite. The Sun is on its first and only life. However, all of the elements except hydrogen and helium were created in earlier stars. Elements lighter than iron were created in main seqence stars that, during their red giant stage expelled much of their mass to form a planetary nebula which later dispersed into the interstellar medium. Elements heavier than iron were formed in supernovae and were dispersed in the explosion. The shockwaves from the supernovae compressed interstellar gas and dust, which collapsed to start the proceedure all over again.

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thanks - I oviously mis understood tuckerfans' post, as I had a bizarr picture of the sun re forming its' self (!) which was a new on me

the ultimate recycling machine makes heaps more sence and is how I understood things to be.

how many generations can a star have, how many will our sun have

See Kaptain K's reply above. Stars only get one lifetime and it's no different for ours. The first generation of stars to form after the Big Bang were composed of primarily hydrogen and helium, since that was all there was. As these stars evolved to become planetary nebulae or supernovae they ejected heavier elements that had been fused during their lifetimes. These heavier elements were eventually incorporated into future stars when they formed.

Our sun will evolve to be a Red Giant and will eventually eject its outer layers as a planetary nebula which may someday be incorporated into a new star. The remaining exposed, dense core is called a White Dwarf which is glowing white hot from the leftover energy that was released when it was still fusing. The White Dwarf is no longer fusing and no new energy is being generated. The White Dwarf will eventually cool off and at sometime in the future will no longer be detectable in the visible spectrum of light.

I hope this makes sense.

This is actually not true. Most elements lighter than iron (e.g., oxygen, neon, magnesium, silicon) were created in high-mass stars that later exploded. They did not form planetary nebulae. The most prominent exception is nitrogen, which WAS created largely in low-mass stars that formed planetary nebulae. Also, some and possibly most carbon was made in this way.

Many elements heavier than iron--such as gold and platinum--were indeed created by the r-process, probably in supernovae; but some--such as strontium, yttrium, and barium--were created via the s-process, in red giants and supergiants.

I think the usual term is 'population'. Sol is considered a Population II star, AFAIK.

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No, Population is a different term altogether. The stars in our galaxy are divided into two large groups: Population I and Population II. Pop I stars (including our Sun) are found in the galactic plane, the spiral arms and open clusters. They are typically younger than Pop II stars and are rich in heavy elements. Pop II stars are mainly older, and are considerably poorer in heavy elements. They are found in a spherical halo surrounding the galactic centre, and also in globular clusters.

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Ok, I guess I should've read that chapter more carefully...

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