The Apsidal Motion and Radius of Gyration of the Proton-Proton Solar Model.

The apsidal motion constant, k, and the radius of gyration, H/R, are calculated for the recently integrated proton-proton model of the sun. It is found that the apsidal-motion constant gives a value of the effective polytropic index which is smaller than one is led to expect from observational data. The value of the radius of gyration obtained places the model off the straight line that was previously found to exist between -log k and -log H/R for main-sequence stellar models.