[Mesa-users] How is defined the upper limit of the star core?

[Bill Paxton]

> On Sep 15, 2018, at 3:30 PM, Roque Caballero Navarro via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Hi there,
> 
>    How is defined the upper limit of the star core? For example, I'm 
> using the following stop condition for finishing the simulation where 
> the TAMS is reached:
> 
>       ! stop when the center mass fraction of h1 drops below this limit
>       xa_central_lower_limit_species(1) = 'h1'
>       xa_central_lower_limit(1) = 1d-9
> 
> Which condition determines the outermost limit of the center?
> 
> Kind regards,
> 
> Roque


here’s how to dig out that info for yourself.  hopefully this example will provide a method that will be useful to you and others in the future.

1) cd mesa/star/private
2) grep xa_central_lower_limit *.f90; find this
	do_one_utils.f90:            if (avg_x < s% xa_central_lower_limit(j)) then
3) open do_one_utils.f90 in editor
4) search for xa_central_lower_limit; find this
            avg_x = center_avg_x(s,i)
            if (avg_x < s% xa_central_lower_limit(j)) then
               call compare_to_target('have dropped below central lower limit for ' // &
                     trim(s% xa_central_lower_limit_species(j)), &
                     avg_x, s% xa_central_lower_limit(j), t_xa_central_lower_limit)
               exit
            end if
5) search for center_avg_x and find this
         use report, only: center_avg_x, surface_avg_x
6) open report.f90 and search for function center_avg_x; find this
            if (sum_dq+dq >= s% center_avg_value_dq) then
7) open star/defaults/controls.defaults and search for center_avg_value_dq; find this
         !### center_avg_value_dq
        ! reported center values are averages over this fraction of star mass
     center_avg_value_dq = 1d-8

Now, if you don’t know what dq is, that’s your next question.  Try to answer it yourself before asking mesa-users.   But if you get stuck, then for sure go ahead and ask.   Just make some effort to answer your question yourself before asking for help.

cheers
Bill


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