[Mesa-users] What does this warning mean?

[Noah Tuchow]

Hello,

I'm trying to model a 1.36 Msun star, analogous to Theta Cygni, and when I
try running a model with diffusion and convective overshoot, I get warning
messages such as the following during its evolution:

exit at x=        0.6168E+15
  more than nmax =        1000 steps are needed

and also it prompts a retry:

retry because of timestep limit diff steps     100       7     100

This causes MESA to run very slowly, and I'm not sure if I can trust the
end results. MESA exits prematurely before H depletion or the maximum age,
because in my run_star_extras I have it exit if the time step becomes too
small.  What does this exit at x message mean? Which aspect of the code is
printing it to the screen?

Perhaps this is due to the inlist I am using, which is slightly modified
from a solar model I was running. Do you know how I can avoid this problem
in the future, while also including diffusion in my model? This star should
have a pretty thin outer convective zone, so maybe that is causing a
problem.

I've attached the inlist I've been using in MESA 11701 and my
run_star_extras.

Any ideas about how to resolve this problem?

Thanks,
Noah Tuchow
---Noah TuchowPenn State UniversityDepartment of Astronomy and Astrophysics532C
Davey LabUniversity Park, PA 16802
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