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

[Pau A.S.]

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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