[Mesa-users] Primary star evolution stalled in binary simulation

[Gökhan Yücel]

Hi Alex,

I have tried binary evolution with your settings and files and I had the
same result as you. I think the problem that the second star, which is the
accretor in this setup, can't adapt the material, which comes from the
donor star. Later on, I have checked your files and saw that your
run_binary_extras.f90 file is heavily edited, which is good. MESA is
exactly for that!

However, this also comes with a price that things can go wrong absurdly. My
humble advice on this that do the same experiment without extra routines
that you wrote for run_binary_extras.f90 file. May be, just delete the
extra subroutines one by one to see which subroutines affect this
phenomenon.

I hope this would help for your experiments.

Note: I have run your settings with v23.05.1 with ZAMS patch
("zams_z2m2_y28_patched.data").

Best,
*Gökhan Yücel*, Ph.D.



On Sun, Aug 31, 2025 at 8:27 AM Alex Duran via Mesa-users <
mesa-users at lists.mesastar.org> wrote:

> Hi all,
>
> I'm trying to evolve a binary model grid to study mass transfer. While
> analyzing a particular system, I notice that, at some point in the mass
> transfer phase, the code solver has trouble developing the primary (donor)
> star; this can be seen in the HR diagram, as loops in Teff and luminosity
> (attached image). The retries look something like this:
>
>  retry: get_T_tau -- L <= 0    2032
>  retry    2032
>  retry: get_T_tau -- L <= 0    2032
>  retry    2032
>  retry: get_T_tau -- L <= 0    2032
>  retry    2032
>  retry: get_T_tau -- L <= 0    2032
>  retry    2032
>  retry: get_T_tau -- L <= 0    2032
>  retry    2032
>  retry: get_T_tau -- L <= 0    2032
>  retry    2032
>  retry: get_T_tau -- L <= 0    2032
>  retry    2032
>  retry:  logT > hydro_mtx_max_allowed_logT          68    2032
>  retry    2032
>  retry:  adjust_correction failed in eval_equations -- give up in solver
>  2032
>  retry    2032
>
> After a long effort varying parameters in the inlists, I discovered that
> the problem is solved by disabling the *do_jdot_ml* parameter. However,
> this can be a problem for my analysis, since I am interested in studying
> how different sources of angular momentum loss affect mass transfer. Has
> anyone ever encountered this problem? And if so, how did they solve it? I
> am attaching the inlists (for stars and binary), and also the extras files
> (for both star and binary evolution). The files I attached correspond to
> M1=1 Msun, M2=0.5 Msun and Porb=3.839 days, but I am having the same
> problem for periods between ~2 and ~14 days, for the same combination of
> masses.
>
> Thank you in advance,
> Cheers
> --
> *Alex Durán-Reyes*
> *MSc in Astrophysics, Universidad de Valparaíso*
> *PhD Student in Astrophysics, Universidad de Valparaíso*
> alex.duran at postgrado.uv.cl
> alex.fabian.dr at gmail.com
> _______________________________________________
> mesa-users at lists.mesastar.org
> https://lists.mesastar.org/mailman/listinfo/mesa-users
>
>
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