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

[Francis Timmes]

hi jelena,

> time step drops drastically (even to 10^-2) once the star enters helium core burning phase.

yes. this is a known feature in public release 12778.
at this time, i cannot offer a remedy better than what you are using.

fxt






> On Jul 9, 2020, at 12:32 PM, Jelena Petrović <jpetrovic at aob.rs> wrote:
> 
> 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
> 
> -------------------------------------
> Dr. Jelena Petrovic
> Senior Research Associate
> Astronomical Observatory Belgrade
> Serbia
> -------------------------------------
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