[Mesa-users] Steps to evolve a Sun-lie star with extra input of energy

[Francis Timmes]

hi pau,

a comparison one could make is with the 2019 summer school material

https://jschwab.github.io/mesa-2019/

where extra energy is injected into a model using a run_star_extras.
otherwise, do the experiment with your inlists!

fxt





> On Dec 16, 2022, at 3:30 AM, Pau A.S. via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Dear all,
> 
> I am interested in injecting uniformly a given amount of extra heat but only for a given amount of time. Something like a perturbation to the surface of the star which is of solar type.
> 
> I am wondering what is the best way of doing it. 
> 
> Right now I am doing it by (1) creating a Sun-like star and saving the model, (2) loading it in a different work directory and injecting an amount of energy A for a given time, which I save to a second model and (3) loading this last model and finally evolving it.
> 
> Since I am not experienced in MESA I would really appreciate it if someone could check whether the steps make sense and are correct.
> 
> Thanks!
> 
> Pau
> 
> This is what I am doing:
> 
> (1) Create an initial model which creates a Sun-like star using this inlist_project
> Here the question is when do I stop the run. I have noticed that there is the possibility of using
> 
> 
>    ! Stop when the age of the star exceeds this value (in years). only applies when > 0.
> 
>      max_age_in_days = X
>      max_age_in_seconds = -1
> 
> But I am confused to the comment "(in years)" if the variable is using the word "days".
> 
> -------------------------------------- inlinst_project1 
> &star_job
>   ! see star/defaults/star_job.defaults
>     relax_initial_y = .true.
>     relax_initial_z = .true.
>     new_y = 0.269
>     new_z = 0.0187
> 
>   ! save a model at the end of the run
>     save_model_when_terminate = .true.
>     save_model_filename = '1M.mod'
> 
> / ! end of star_job namelist
> 
> &eos
>   ! eos options
>   ! see eos/defaults/eos.defaults
> 
> / ! end of eos namelist
> 
> 
> &kap
>   ! kap options
>   ! see kap/defaults/kap.defaults
>   Zbase = 0.0187
> 
> / ! end of kap namelist
> 
> 
> &controls
>   ! see star/defaults/controls.defaults
> 
>   ! starting specifications
>     initial_mass = 1 ! in Msun units
>     mixing_length_alpha = 2.22
> 
>   ! input physics
>     do_element_diffusion = .true.
> 
>    ! Stop when the age of the star exceeds this value (in years). only applies when > 0.
> 
>      max_age_in_days = X
>      max_age_in_seconds = -1
> 
>   ! asteroseismology
>     write_pulse_data_with_profile = .true.
>     add_atmosphere_to_pulse_data = .true.
>     profile_interval = 20
> 
> / ! end of controls namelist
> --------------------------------------------------------------------------
> 
> (2) Use that model to inject a uniform extra heat
> 
> I would then load that model and add the extra heat I want via this inlist_project2
> 
> ----------------------------------------------------------------------------------------------- inlist_project2
> &star_job
>   ! see star/defaults/star_job.defaults
> 
>   ! start a run from a saved model
>   load_saved_model = .true.
>   load_model_filename = '1M.mod'
> 
>   ! save a model at the end of the run
>     save_model_when_terminate = .true.
>     save_model_filename = '1M_extra_energy.mod'
> 
> / ! end of star_job namelist
> 
> 
> &eos
>   ! eos options
>   ! see eos/defaults/eos.defaults
> 
> / ! end of eos namelist
> 
> 
> &kap
>   ! kap options
>   ! see kap/defaults/kap.defaults
>   Zbase = 0.0187
> 
> / ! end of kap namelist
> 
> 
> &controls
>   ! see star/defaults/controls.defaults
> 
>   ! starting specifications
>     initial_mass = 1 ! in Msun units
>     mixing_length_alpha = 2.22
> 
>    inject_uniform_extra_heat    = A # erg g^-1 s^-1
>    min_q_for_uniform_extra_heat = B #  bottom of region for inject_uniform_extra_heat
>    max_q_for_uniform_extra_heat = 1 #  sets top of region for inject_uniform_extra_heat
> 
>   ! input physics
>     do_element_diffusion = .true.
> 
>    ! Stop when the age of the star exceeds this value (in years). only applies when > 0.
> 
>      max_age_in_days = X
>      max_age_in_seconds = -1
> 
>   ! asteroseismology
>     write_pulse_data_with_profile = .true.
>     add_atmosphere_to_pulse_data = .true.
>     profile_interval = 20
> 
> / ! end of controls namelist
> -------------------------------------------------------------------------------------------------------- 
> 
> (3) Finally, run the perturbed star with the extra amount of energy up to e.g. the SGB
> 
> ----------------------------------------------------------------------------------------------------- inlist_project3
> &star_job
>   ! see star/defaults/star_job.defaults
>   ! start a run from a saved model
>   load_saved_model = .true.
>   load_model_filename = '1M_extra_energy.mod'
> 
> / ! end of star_job namelist
> 
> 
> &eos
>   ! eos options
>   ! see eos/defaults/eos.defaults
> 
> / ! end of eos namelist
> 
> 
> &kap
>   ! kap options
>   ! see kap/defaults/kap.defaults
>   Zbase = 0.0187
> 
> / ! end of kap namelist
> 
> 
> &controls
>   ! see star/defaults/controls.defaults
> 
>   ! starting specifications
>     initial_mass = 1 ! in Msun units
>     mixing_length_alpha = 2.22
> 
>     log_Teff_lower_limit = 3.751
> 
>   ! input physics
>     do_element_diffusion = .true.
> 
>   ! asteroseismology
>     write_pulse_data_with_profile = .true.
>     add_atmosphere_to_pulse_data = .true.
>     profile_interval = 20
> 
> / ! end of controls namelist
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