Talk:Carbon-burning process

Wrong

It says:

Carbon burning starts when helium burning ends...

No. In principle, there can be overlaps, see Supernova. The onion burning progenitors burn carbon and helium simultaneously. Said: Rursus (☻) 11:25, 24 October 2008 (UTC)

I guess the point is that when helium density drops sufficiently, helium fusion no longer produces enough energy in the core to prevent the core from contracting significantly. I also assume that the core becomes gradually more compact and hotter as the helium gets used up, and the helium fusion will proceed faster. The inert products of the helium burning must also build up in the core: whilst the core is not hot enough to fuse these they will not contribute to the gas pressure keeping the core from contracting.

So I would conclude that the final stage of helium buring before the core contracts and ignites carbon fusion would proceed much faster as fusion is very sensitive to increases in temperature. It might be a close thing as to whether the helium in the core runs out before or after the carbon fusion begins, and might depend on the mass, metallicity and other properties of the star. Perhaps the article would be correct if the statement Carbon burning starts when helium burning ends were changed to something like Carbon burning starts when the amount of helium in the core drops below a level where helium fusion alone produces sufficient energy to maintain the star in hydrostatic equilibirum but this seems a bit of a mouthful... Puzl bustr (talk) 18:10, 24 September 2009 (UTC)

Added a term for the energy produced for the Mg-23 process, calculated from the masses of the terms in AMU. Puzl bustr (talk) 14:03, 25 September 2009 (UTC)

Added a reference for the nuclear equations Puzl bustr (talk) 20:29, 9 October 2009 (UTC)

What we like to do for the OP's point is make a distinction between hydrostatic and explosive carbon burning. In the former case, the the quoted text purported to be wrong is correct. This is also a useful way to keep the article from having too many qualifiers. In this sense, after a general description which applies to all types of carbon burning, the major sections should be quiescent and explosive (or hydrostatic and non-equilibrium...whichever terms you prefer). DAID (talk) 18:04, 18 November 2009 (UTC)

Added references and cleaned up the discussion

I re-wrote the section to remove an erroneous (for masses below 10 solar) reference to red supergiant stars and instead mention Asymptotic Giant Branch stars. I used the Ostlie reference to expand the discussion of carbon fusion and explain the basic variations depending on the mass of the star. Hope this is enough to reduce the warnings on the page.Puzl bustr (talk) 12:03, 17 October 2009 (UTC)

Good! Although the concept red giant is vague and does include AGB stars, supergiants seems fairly irrelevant. Warnings not needed any more. BTW I found an ADSABS entry for that Donald Clayton book, that I included in the ref. In this case it doesn't matter much, but in ADSABS one may find very interesting reading when articles are freely available. ... said: Rursus (^mbork³) 18:20, 17 October 2009 (UTC)

If we are worried about distinguishing red giants and AGB stars from things like the sun, I suggest the term "non-main-sequence stars" or something similar. Of course this has it's own problems, like including white dwarfs, but if the noun is non-main-sequence stars with (eg: red giants, AGB stars ...) then I think it's more clear. As a side note, articles on ADS are generally not free and are linked to the respective journals. It's only "free" if your institution is paying, or if it's on arXiv.org DAID (talk) 18:07, 18 November 2009 (UTC)

Added Google books references for the Reaction Products section

I added these references as open-access ones. Also added a section on neutrino losses with the Clayton ref.Puzl bustr (talk) 21:11, 19 October 2009 (UTC)