by rstevenson » Thu Aug 19, 2010 3:44 pm
Chris Peterson wrote:rstevenson wrote:4.-So, the stars we see formed from dust and / or molecular matter, if they lack hydrogen, may shine like stars for its plasma state, but may not synthesize elements from the duplication of atoms.
You're thinking of hydrogen burning in stars. But there are also the processes of helium burning, carbon burning, neon burning, oxygen burning and silicon burning, all of which contribute to the creation of heavier elements. See the Wikipedia page on
Nucleosynthesis.
Yes, but AFAIK there are no stars that form without hydrogen as their main constituent. Stars
evolve to states that fuse something other than hydrogen, but they never start that way.
True, but I think León was wondering if a star
could form without hydrogen, and if so, would nucleosynthesis progress. The reason stars seem to always include so much hydrogen is simply that there is so much of it to include. But if we imagine a region of space containing sufficient gas and dust, which happens to contain little or no hydrogen, then I suppose (under those
extremely unlikely conditions) a star could indeed form. And if it formed, I see no reason why some form of nucleosynthesis could not happen, though likely not the usual processes and not to the same extent.
[added moments later, after I saw Chris' post above]
As for this being an unscientific discussion, and therefore inappropriate to the Asterisk, I beg to differ. I can see exactly this question being proposed in an Astronomy class, the purpose being to prompt students to go off and find out all sorts of things to either support or reject the proposal. The main thing they'd need to do in support of the idea is propose a mechanism by which a cloud of gas and dust sufficently large to coalesce into a star could form without including any significant amount of hydrogen. I
suspect it's not possible, but that doesn't make this an unscientific discussion. Perhaps you
know it's not possible?
Rob
[quote="Chris Peterson"][quote="rstevenson"][quote]4.-So, the stars we see formed from dust and / or molecular matter, [color=#804000]if they lack hydrogen[/color], may shine like stars for its plasma state, but [color=#804000]may not synthesize elements[/color] from the duplication of atoms.[/quote]
You're thinking of hydrogen burning in stars. But there are also the processes of helium burning, carbon burning, neon burning, oxygen burning and silicon burning, all of which contribute to the creation of heavier elements. See the Wikipedia page on [url=http://en.wikipedia.org/wiki/Nucleosynthesis]Nucleosynthesis[/url].[/quote]
Yes, but AFAIK there are no stars that form without hydrogen as their main constituent. Stars [i]evolve[/i] to states that fuse something other than hydrogen, but they never start that way.[/quote]
True, but I think León was wondering if a star [i]could[/i] form without hydrogen, and if so, would nucleosynthesis progress. The reason stars seem to always include so much hydrogen is simply that there is so much of it to include. But if we imagine a region of space containing sufficient gas and dust, which happens to contain little or no hydrogen, then I suppose (under those [i]extremely[/i] unlikely conditions) a star could indeed form. And if it formed, I see no reason why some form of nucleosynthesis could not happen, though likely not the usual processes and not to the same extent.
[added moments later, after I saw Chris' post above]
As for this being an unscientific discussion, and therefore inappropriate to the Asterisk, I beg to differ. I can see exactly this question being proposed in an Astronomy class, the purpose being to prompt students to go off and find out all sorts of things to either support or reject the proposal. The main thing they'd need to do in support of the idea is propose a mechanism by which a cloud of gas and dust sufficently large to coalesce into a star could form without including any significant amount of hydrogen. I [i]suspect[/i] it's not possible, but that doesn't make this an unscientific discussion. Perhaps you [i]know[/i] it's not possible?
Rob