[Mesa-users] Stellar wind & time step for massive helium core burning stars

[Jelena Petrović]

Dear all,

I am calculating evolution of massive stars, above 30Ms with an option 
for stellar wind:
hot_wind_scheme = 'Dutch'
Dutch_scaling_factor = 1d0

I have noticed that time step drops drastically (even to 10^-2) once the 
star enters helium core burning phase.
However, if I decrease scaling factor, time step increases and if I 
fully switch off stellar wind (scaling_factor = 0d0), helium core 
burning is calculated with time steps of 10^2-10^3.

I have the same problem with massive binaries, where the primary becomes 
WR star, so helium core burning star with most of its hydrogen envelope 
gone.
Also, if I switch of stellar wind, time steps goes from 10^-2 to 
10^2-10^3.

What can be the reason for this? How can I keep a reasonable time step 
with stellar wind option on?

Many thanks,
Jelena

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Dr. Jelena Petrovic
Senior Research Associate
Astronomical Observatory Belgrade
Serbia
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