[Mesa-users] Weird turn points on near TAMS

[Francis Timmes]

i'm not completely clear what you expect the turn-off to be.
if you refer to the swing toward the blue, then this is largely
controlled by the treatment of convective boundaries. attached is
an hr diagram using your use_ledoux_criterion = .false. default, and 
use_ledoux_criterion = .true. for the 1.22 msun case.

fxt




> On Aug 2, 2021, at 7:32 AM, Gökhan Yücel <gokhanyucel at akdeniz.edu.tr> wrote:
> 
> Hello Francis,
> 
> Thanks for suggestion. In my first inlist, maximum time step was set as 10^7 years. I thought it was enough for details. 
> 
> Anyhow, I have followed your suggestion as,
> 
> 1. Make a single evolution until the Hcenter to drop 0.2 with timestep 10^7 years(for saving time), and when it is reached to 0.2 Hrich, save the model.
> 
> 2. Start the evolution with saved model with timestep 10^5 years, which is roughly delta-lg-xh-cntr-limit=1d-4, and stop it on an arbitrary phase in the evolution.
> 
> I have done this with mass range between 1.21 and 1.27 Msun. Unfortunately, as you can see from attached eps file, the result hasn't changed which indicates that the resolution wasn't the problem. There is a still weird, at least not expected, turn-off position on HR diagram.
> 
> I'm open to any help. I'm using r-12115.
> 
> Regards,
> Gökhan.
> ________________________________________
> Kimden: Francis Timmes [fxt44 at mac.com]
> Gönderildi: 30 Temmuz 2021 Cuma 18:31
> Kime: Gökhan Yücel
> Bilgi: Frank Timmes; mesa-users
> Konu: Re: [Mesa-users] Weird turn points on near TAMS
> 
> hi gökhan,
> 
> the inlist suggests the runs are relying on the default mass & timestep resolution settings.
> you may want to consider using smaller timesteps using physically based controls
> and/or finer mass resolution - especially as a fuel depletes in the core.
> 
> examples include
> 
> https://docs.mesastar.org/en/latest/reference/controls.html#timestep-controls
> https://docs.mesastar.org/en/latest/reference/controls.html#delta-lgt-cntr-limit
> https://docs.mesastar.org/en/latest/reference/controls.html#delta-lgrho-cntr-limit
> https://docs.mesastar.org/en/latest/reference/controls.html#delta-lg-xh-cntr-limit
> https://docs.mesastar.org/en/latest/reference/controls.html#max-dq
> 
> fxt
> 
> 
> 
> 
> 
>> On Jul 29, 2021, at 5:29 AM, Gökhan Yücel <gokhanyucel at akdeniz.edu.tr> wrote:
>> 
>> Sorry, forgot to add. I'm using MESA version of 12115
>> 
>> ________________________________________
>> Kimden: Gökhan Yücel
>> Gönderildi: 29 Temmuz 2021 Perşembe 15:26
>> Kime: mesa-users at lists.mesastar.org
>> Konu: Weird turn points on near TAMS
>> 
>> Hello everyone,
>> 
>> I have encountered a weird point while doing evolution of a single, rotating stars with different masses between 1.20 and 1.26 M. As you can see from the attachment, the turn off points of near TAMS do not behave as expected. There is a quite differences. Is there a some stellar interior mechanic that affects to make it behave like this in this mass range that I don't know about it, or am I doing something wrong?
>> 
>> There is nothing extra settings in "run_star_extras.f" file.
>> 
>> Thanks in advance,
>> Gökhan
>> <sample.eps><inlist_project>_______________________________________________
>> mesa-users at lists.mesastar.org
>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>> 
> 
> <sample.eps><inlist_project>



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