[Mesa-users] Mass loss in low mass star during PMS

[Roque Caballero Navarro]

HI Warrick,

   Many thanks for sharing your approach. I'll dive into the the winds.f90 module.

Kind regards,

Roque
________________________________
De: Warrick Ball <wball at bison.ph.bham.ac.uk>
Enviado: miércoles, 18 de abril de 2018 8:10
Para: Roque Caballero Navarro
Cc: Francis Timmes; mesa-users at lists.mesastar.org
Asunto: Re: [Mesa-users] Mass loss in low mass star during PMS

Hi Roque,

I don't personally use the wind routines but you can possibly answer some
of your own questions by having a look at the source code.  This is often
my next step if the documentation in the defaults doesn't give enough
detail on how a particular control, set of controls or part of the
whole evolution calculation works.

I usually start by finding a relevant control and then search for it in
the source.  For example, let's find `cool_wind_full_on_T`:

$ grep -n cool_wind_full_on_T $MESA_DIR/star/p*/*.f*
/home/wball/mesa/10398/star/private/winds.f90:391:         if(s% hot_wind_full_on_T < s% cool_wind_full_on_T)then
/home/wball/mesa/10398/star/private/winds.f90:393:            write(*,*) ' *** set_mdot error: hot_wind_full_on_T < cool_wind_full_on_T '
/home/wball/mesa/10398/star/private/winds.f90:397:         if(T1 >= s% cool_wind_full_on_T)then !do hot_wind calculation
/home/wball/mesa/10398/star/private/winds.f90:421:         else if(T1 <= s% cool_wind_full_on_T)then
/home/wball/mesa/10398/star/private/winds.f90:424:            if(s% hot_wind_full_on_T == s% cool_wind_full_on_T)then
/home/wball/mesa/10398/star/private/winds.f90:427:               divisor = s% hot_wind_full_on_T - s% cool_wind_full_on_T

>From that point, I often find myself following various subroutine calls
until I find where the work is actually done but in this case it's
straightforward.  The (sensibly named!) file `star/private/winds.f90` is
where to look.

I glanced at the section containing `cool_wind_full_on_T` and I think it
should explain how MESA decides which wind scheme to use.  The wind
calculations are in a separate subroutine to the decision-making logic so
you can go through the latter without having to fuss with the various
formulae.

Good luck!

Cheers,
Warrick



------------
Warrick Ball
Postdoc, School of Physics and Astronomy
University of Birmingham, Edgbaston, Birmingham B15 2TT
wball at bison.ph.bham.ac.uk
+44 (0)121 414 4552

On Wed, 18 Apr 2018, mesa-users at lists.mesastar.org wrote:

> Dear Francis,
>
>   Many thanks for your feedback. Before it, I was testing the following configuration (copied from a test):
>
>  ! mass loss
>  cool_wind_full_on_T = 4.3d3
>  cool_wind_RGB_scheme = 'Reimers'
>  RGB_to_AGB_wind_switch = -1
>  Reimers_scaling_factor = 0.5d0
>
>   Does it make sense for you to use the "cool_wind_full_on_T" parameter. I understood that this one governs when the wind routine is started. Should it be also used the "cool_wind_AGB_scheme" one?
>
> Kind regards,
>
> Roque
> ________________________________
> De: Francis Timmes <fxt44 at mac.com>
> Enviado: martes, 17 de abril de 2018 23:06
> Para: Roque Caballero Navarro
> Cc: Frank Timmes; mesa-users at lists.mesastar.org
> Asunto: Re: [Mesa-users] Mass loss in low mass star during PMS
>
> hi roque,
>
> if one has a known mass loss rate to impose, it can be as simple as
>
> mass_change = value  ! in msun/yr
>
> http://mesa.sourceforge.net/controls_defaults.html#mass_gain_or_loss
>
> something fancier like
>
>      cool_wind_RGB_scheme   = 'Reimers'
>      cool_wind_AGB_scheme   = 'Blocker'
>      RGB_to_AGB_wind_switch = 1d-4
>      Reimers_scaling_factor = 0.1
>      Blocker_scaling_factor = 0.5
>
> will have a small mass loss during the main sequence,
> which you can test for yourself by examining the history of
>
> star_mdot
>
>
> fxt
>
>
>
>
>
>> On Apr 17, 2018, at 12:21 PM, Roque Caballero Navarro via Mesa-users <mesa-users at lists.mesastar.org> wrote:
>>
>> Dear all,
>>
>>    I'm modeling the evolution of a star with 1 solar mass from the PMS till the TAMS and I want to activate the mass loss option during the simulation. According to MESA documentation it seems to me that this process takes only place during the RGB and AGB evolution phases. So, my question is: is it possible to model mass loss in early stages as the PMS and MS of a low mass star? If so, could you let me know which options should I select?
>>
>>     Many thanks in advance.
>>
>> Kind regards,
>>
>> Roque
>>
>> _______________________________________________
>> mesa-users at lists.mesastar.org
>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>>
>
>
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