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

[Bill Paxton]

the inlist you sent runs to core collapse, but for the current question, we should change that to stop when the mass loss is (mostly) complete, just long enough to show the problem.  any convergence runs you do for this can stop at that point and save some time.

b


> On Mar 9, 2020, at 9:15 AM, Bill Paxton <paxton at kitp.ucsb.edu> wrote:
> 
> Hi Hannah,
> 
> I’m curious about this too.  So i’ll checkout those versions and try running your inlist and run_star_extras.  Will they work in both mesa versions?   if not please send me something that does.
> 
> You could also help clarify this question by checking convergence for your runs on both systems - is the change in mass loss relatively small when you make ‘large’ changes in the time or space resolution (large meaning ~50% or so)?  as part of this, please make plots of mdot, R, L, M, number of zones, and number of timesteps vs. log age.  are they converged?  do they look similar for both mesa versions?  also, include any other surface properties that your mass loss routines consider - e.g., Fe_div_Fe_solar for the outermost cell.   i’d be interested in seeing all of those plots.   they will go a long way toward telling us what has changed for the new mesa version.
> 
> my main interest will be on changes in converged results, since for unconverged results the details of the numerics play a large role.  so please send along your results showing convergence so we know we are comparing “physics" rather than implementation details.    if the converged results have changed by such a large amount then we really have something interesting to consider!
> 
> let me know what you find.
> 
> cheers,
> bill
> 
> 
> 
>> On Mar 6, 2020, at 7:29 AM, 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
>> <inlist_project><run_star_extras.f>_______________________________________________
>> mesa-users at lists.mesastar.org
>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>> 
>