[Mesa-users] other_wind vs other_adjust_mdot

[Jared Goldberg]

Hi Abha,

For your case, it sounds like other_wind will work.

For some recent tutorial material, we discuss implementing an other_wind in
the Tuesday Minilab 3 of the 2024 MESA Down Under "Summer" (winter)
school, linked
here <https://sites.google.com/view/massive-stars-mesa-down-under/minilab3>
.

In general, both other_wind and other_adjust_mdot can be used for mass
loss. Other_adjust_mdot digs a bit more into the guts of the star, setting
the mdot parameter in the star pointer (s% ) and modifying it directly.
Since other_adjust_mdot can be positive or negative, it's good for
accretion or other schemes where the star is allowed to either gain or lose
mass. Other_wind is purely for mass *loss*; it is called relatively early
in the evolution loop, before some variables are set (which if needed, you
can get around by actively initializing the star pointer, as we do in Lab 3
Task 2 of the linked lab). The advantage of using other_wind is that it
enforces mdot <= 0, so your mass loss scheme will not accidentally become
accretion as a result of numerical or implementation errors. Additionally,
other_wind takes in surface properties of the star and does not require
access to the full star pointer (though you can initialize the star pointer
s% and use it if needed).

Hope this helps!

Cheers,
~Jared

On Wed, Jun 26, 2024 at 10:56 PM Abha Vishwakarma via Mesa-users <
mesa-users at lists.mesastar.org> wrote:

> Dear MESA Users,
>
> I wanted to implement a custom mass loss scheme from the surface of a red
> giant star, but I am confused between the two choices - using other_wind or
> other_adjust_mdot . I would like to remove mass using an exponential mass
> loss function that depends on time. Currently, the key difference that I
> know is that I need to set the " w " parameter in other_wind , whereas in
> the  other_adjust_mdot hook I need to set " s% mstar_dot ". I think the
> other_wind hook should work, but should I use it?
>
> I would like to know which of these would be relevant for my case, and get
> some insight into the differences between these two hooks.
>
> Best,
> Abha
>
> -----------------------------------------------------------------
> *Abha Vishwakarma*
> Final Year Int. M.Sc.
> NISER, India
> Mail: abha.vishwakarma at niser.ac.in
> Web: sites.google.com/view/abhavishwakarma/
>
>
> _______________________________________________
> mesa-users at lists.mesastar.org
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>
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