[Mesa-users] Massive star evolution after CO core formation

[Jelena Petrović]

Dear all,

I am evolving massive stars (above 30Ms) and I have noticed that most of 
my models have problems evolving further than CO core,
time steps get really small and models do not progress anymore.
Only sometimes I manage to get the evolution all the way to Fe core. It 
seems that lower mass models do slightly better.

I though this is because of extended hydrogen envelope, so I have tried 
to evolve helium stars. However, the same happens.
When the core is about 25% C and 75% O, the models run, but with 
extremely small time steps.
Just to note that stellar wind is also switched off to ensure that this 
is not the reason for smaller time steps.

Does anybody know what could be the problem?

Many thanks!
Jelena

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Dr. Jelena Petrovic
Senior Research Associate
Astronomical Observatory Belgrade
Serbia
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