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I need to knit pick here 8o)
On Tue, 27 Sep 1994, Jason Rogers wrote:
*snip*
> In a large star (I think about twice ours or more, but I don't have the
> figures) as the hydrogen runs out the innner part of the star contracts and
> heats up. (in our star the end will be different, but this bit is much the
> same) The outer part of the star will expand, as it is held up by the greater
> flux of radiation pressure generated by the hotter interior. It will now
Actually expansion is caused by conservation of angular momentum.
As the inner part of the start contracts, the outter must expand in
order to conserve angular momentum. Expansion is halted by the increase
in radiation pressure that comes about for the collapsing core.
> start "burning" the helium and as that runs out, other elements.
> These reactions produce less energy than the hydrogen burning and the star
> contracts further in the center. Eventually an "ash of a hard to fuse element
> builds up in the centre of the star. (I think it's oxygen, but don't quote
me)
Depends on the size of the star, larger ones could have iron cores toward
the end of their lives.
*snip*
> Eventually the stars fires go out and it collapses gravitaionally. The center
> all fuses at once and all the elements we know that are above oxygen on the
> periodic table get created all at once. This blows the star to bits and the
It's actually above what ever the star core consists of, large stars will
have iron.
> new elements are spewed out all over at great speed. This is were most of the
> stuff that makes up your body (and the earth) were created. Making these
> elements requires that energy is put in (oposite to making the lighter
> elements where you get energy out) so most of these elements "want" to break
> up and make iron56 which is the lowest energy element. They do this by
> emitting an Alpha particle (He atom without electrons). This is called
> "radioactivity" and is the source of Helium we use here on earth.
*snip*
Helium would be a lot more expensive if it was distilled from the air.
There is very little helium present in the air.
Cheers!
Shane
--
\
To go o/\__ Shane Jensen
where only < \__,\ (602) 621-2054
lizards have "> . | Steward Observatory
gone before. ` .-\ jensen@as*.ar*.ed*
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