[Mesa-users] Hydrogen core mass and radius

[Aaron Dotter]

Hi Roque,


      !h_rich_layer_mass ! = star_mass - he_core_mass
>       !he_rich_layer_mass ! = he_core_mass - c_core_mass
>       !c_rich_layer_mass ! = c_core_mass - o_core_mass
>       !o_rich_layer_mass ! = o_core_mass - si_core_mass
>       !si_rich_layer_mass ! = si_core_mass - fe_core_mass
>
> I'm wondering if the mass of the hydrogen core (similarly for the radius) can
> be derived by subtracting the star mass the masses of the other cores (He,
> C, O, Si and Fe)
>


No, it cannot.  The other cores refer to later stages of nuclear burning
after the H in the core has been exhausted.  If you try plotting them,
you'll see they're all zero during core H-burning (main sequence).

For example, the he_core_mass can be defined because there is a region of
the star that is free of H.  In the case of core H-burning, we cannot
simply perform a test on the presence or absence of an element because
there is H throughout the star.

Are you using profiles or the history file?  In the profile you might
consider plotting the luminosity from H-burning (log_LH or similar) and see
how it changes with radius and mass.

Aaron
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