[mesa-users] Help with MESA: Definition of Core masses

[Josiah Schwab]

Hi Hannah,

> I'd like to know what the program uses as a definition for the
> core-masses.

By default, the core boundaries are determined by the point at which the
"previous" isotope decreases below some abundance threshold and the
where the "new" isotope is above some abundance threshold.

For example, the boundary of the helium core is defined to be the point
(moving inwards) where the h1 mass fraction falls below 0.01
(he_core_boundary_h1_fraction) and the he4 mass fraction is greater than
0.1 (min_boundary_fraction).  Then the he_core_mass is the mass interior
to this boundary location, etc.

You can control the details of this definition.  See the documentation:

http://mesa.sourceforge.net/controls_defaults.html#definition_of_core_boundaries

Best,
Josiah