Inhomogeneous Stellar Models. IV. Models with Continuously Varying Chemical Composition.

Nine sample models are constructed in which the mean molecular weight varies from the center to the surface by a factor of 2.5 and in which this variation occurs continuously inside an intermediate zone. These models are compared with simpler models in which the same composition variation occurs discontinuously at an interface. The comparison shows that the simpler, discontinuous models may be used to compute the luminosity with satisfactory accuracy but that they tend to exaggerate the radii-in certain cases by an order of magnitude.