"palsing" wrote in message...
- a425couple wrote:
- So, the stars had to make the heavier elements.
- Then burn out or blow up to disperse these elements into
- space to renain, or form up in planets, or into other stars.
-
- Do any stars only live 2.8 Billion years (13.8B - 11 B) ?

- The heaviest stars can complete their life cycles in just a few million
years...
- http://en.wikipedia.org/wiki/Star#Massive_stars
- Scroll about 1/3 the way down and look for the "AGE" heading...
- "The more massive the star, the shorter its lifespan, primarily because
-massive stars have greater pressure on their cores, causing them to
-burn hydrogen more rapidly. The most massive stars last an average
-of a few million years, while stars of minimum mass (red dwarfs)
-burn their fuel very slowly and can last tens to hundreds of billions of
years."

Thanks.
and here is something more, also relevant
How Old are the First Planets?
By Keith Cooper - Aug 30, 2012
http://www.astrobio.net/news-exclusi...first-planets/
Heavy Metal Planets
Earth was born out of the debris of a protoplanetary disc around a
nascent Sun 4.54 billion years ago - a serious chunk of time in anybody's
book. Yet the Universe is 13.7 billion years old - the Solar System
has been around for just the last third of cosmic history. Is it possible
that rocky planets could have formed around other stars much earlier?
Are we the new kids on the block by comparison?
"Until recently, we didn't think so. The prevailing wisdom had been that
the magic of stellar alchemy didn't produce enough useful "star-stuff" to
build terrestrial worlds until at least six or seven billion years after the
Big Bang."

""A typical massive star that exploded and released heavy elements 10 to 12
billion years ago had a metallicity of about a tenth of the Sun,"

One of the favorite counter-arguments to the Fermi Paradox was that
the threshold metallicity takes time to build up, resulting in the Sun being
one of the first stars at the required level and hence Earth would be one
of the first planets with life.
!!---- Now we see that planets and possibly life
could have arisen at practically any point in cosmic history, undermining
this counter-argument and once again forcing us to ask, where is everybody?
If life did first appear on worlds 12 to13 billion years ago, then
intelligent
civilizations (if indeed they survived all this time) would now billions of
years ahead of us and their concerns may no longer include the happenings
on a damp mudball somewhere in the galactic hinterlands. -

(I think that idea is nonsense.
How long can any one species live?
If you have evolution, and survival of the fittest, there will
always, and regularly be changes, and the best will survive
and flourish.
Even if it existed, any species 1 B years ago will have been
vanquished long before now.
No single civilization will last billions of years.)