Re: [mesa-users] very thin shell burning

[Falk H. <fh...@uv...>]

Hi Stan, Kent:
>
> On Wed, 2011-03-30 at 08:44 -0700, Stan Woosley wrote:
>> Kent, Falk, et al.,
>>

>>
>> The carbon is converted to nitrogen in the envelope and C << O
>> so it is not clear that grains will form AND

I have no feeling for massive star models in this situation, but for  
the intermediate mass stars, e.g. M_ini=5Msun it is not clear that  
this hot dredge-up or corrosive convection induced H-flame burning  
automatically leads to C<<O. The plot below (Herwig,2004, ApJ 605,  
425) shows the surface abundance evolution of C, N and O during such a  
H-flame burn after a thermal pulse when the envelope convection is  
making contact with the CO-core: