[mesa-users] Accretion: max_star_mass_for_gain and eps_grav

[Josiah Schwab]

Hello Philip,

> I want to use MESA 7624 to model accretion which stops when a chosen
> mass is exceeded. I find strange behaviour when the
> max_star_mass_for_gain parameter is used to achieve this. The strange
> behaviour seems to be because the eps_grav calculation still thinks
> the star is accreting even after the maximum mass is exceeded.

Thank you for this excellent report.  It looks like you uncovered a bug
in the `max_star_mass_for_gain' and `min_star_mass_for_loss' controls.
You may be the first person to use these :)

This will be fixed in the next release.  I will follow up with you
off-list about the specific fix that gets applied.

Until then, if you want to be able to change the accretion rate while
the run is going, you can do the same thing using run_star_extras.f.

Add the following lines to "extras_finish_step"

    ! turn off mass loss when the star grows larger than ? (in Msun)
    if (s% star_mass > s% x_ctrl(1)) s% mass_change = 0

Then, you can specify the meas

&controls

  x_ctrl(1) = 0.6

/

Best,
Josiah