[Mesa-users] Issues with mass loss from 20Msun star

[Hannah Brinkman]

Dear Rob,

Thank you for your response. I am aware of the uncertainties in the stellar
wind prescriptions, and I understand that tweaking the efficiency can solve
my issues.
However, my main issue is that from version 10389 to version 12115 the same
wind prescription can give a factor of about 4 difference in the total mass
loss while in the HRD nothing, as far as I am aware, changes enough to give
such a huge difference. I was wondering whether there might be deeper
underlying reasons for this change in the total mass lost.

With kind regards,
Hannah

Op vr 6 mrt. 2020 om 16:12 schreef Rob Farmer <r.j.farmer at uva.nl>:

> Hi,
>
> >The first issue is, that when using the mass loss as given in the inlist,
> about 11Msun for this star, which is a bit much
>
> Wind mass loss rates from massive stars still have uncertainities in them,
> see for instance
> https://ui.adsabs.harvard.edu/abs/2017A%26A...603A.118R/abstract . So its
> possible for your case that you need to tweak the scaling factors if you
> want more/less mass loss (or choose a different prescription for the mass
> loss).
>
> >Since updating from version 10398 to version 12115, the custom wind
> scheme, following Schootemeijer et al. 2018, is no longer working right,
> making the star lose only 2.5Msun instead of the expected ~10Msun which it
> did in version 10398. However, I cannot find what might be the problem here.
>
> Many thing change in mesa between versions. The wind routines take very
> few inputs (Lsurf, Msurf, Rsurf, Tsurf), maybe try plotting the L,R,T at
> the surface of the star between the two versions and see if you can see
> what is changing in the surface properties which would then drive the
> change in the mass loss rate.
>
> Rob
>
>
> On Fri, 6 Mar 2020 at 10:29, Hannah Brinkman via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
>
>> Dear all,
>>
>> Recently I have been trying to make pre-SN models for a 20Msun star,
>> using the inlist given by  Frank Timmes a couple of weeks ago. The inlist
>> works fine when using the settings given in the inlist. However, I have
>> encountered two issues around the mass loss. The first issue is, that when
>> using the mass loss as given in the inlist, about 11Msun for this star,
>> which is a bit much. And when switching from the exponential overshoot
>> given in the inlist to the step-overshoot I have been using before, the
>> winds become so strong that the star loses 13Msun, which is the entire
>> hydrogen envelope of this star, which should not happen yet for this mass.
>> The second issue that I have encountered is that the wind scheme in the
>> run_star_extras.f has the opposite problem. Since updating from version
>> 10398 to version 12115, the custom wind scheme, following Schootemeijer et
>> al. 2018, is no longer working right, making the star lose only 2.5Msun
>> instead of the expected ~10Msun which it did in version 10398. However, I
>> cannot find what might be the problem here.
>>
>> Does anyone have any idea where these issues might come from? Attached is
>> the inlist I have used and the run_star_extras.f.
>>
>> Thanks in advance for any suggestions.
>> Cheers,
>> Hannah
>>
>
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