[Mesa-users] New to MESA need a bit of understanding

[Nicholas Herrington]

Hi,

Im trying to use the create pre main sequence model along with accretion
controls to take a star and make it super massive. Im using specific
accretion rates in my runs and my issue occurs with each accretion rate.
Whenever I initiate the run, the star accretes matter until a certain mass
(different for each rate) until it stops and prints min timestep error. If
I reduce the min timestep in controls it gets to the same mass as before
but runs for longer on that mass, without accreting any futher, then
finishes with the same error message (even at very small min timestep
values). Ive tried to set the max mass to no limit in the controls but this
hasnt helped either.

I am not sure how the timestep works with this model and why it accretes to
a specific mass everytime reguardless of what time controls I add to the
inlist. If anyone could explain or help me understand what I am doing
wrong, that would be much appreciated.

Thanks
Nick

OS: Linux distro, Pop OS
MESA-r17701
SDK: I downloaded the may 3 2019 version
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&star_job

  ! begin with a pre-main sequence model
    create_pre_main_sequence_model = .true.

  ! save a model at the end of the run
    save_model_when_terminate = .false.
    save_model_filename = 'test.mod'

  ! display on-screen plots
    pgstar_flag = .true.

/ !end of star_job namelist


&controls

  ! starting specifications
    initial_mass = 2 ! in Msun units
    initial_z = 0
    initial_y = 0.2484
    
    star_mass_min_limit = 0
  ! min_timestep_limit = 1d-50

    mass_change = 0.001
    accrete_same_as_surface = .true.
    use_gr_factors = .true.

/ ! end of controls namelist