Analytic Models for the Mechanical Structure of the Solar Core
  All stars exhibit universal central behavior in terms of new homology variables (u,w). In terms of these variables, we obtain simple analytic fits to numerical standard solar models for the core and radiative zones of the ZAMS and present Suns, with a few global parameters. With these analytic fits, different theoretical models of the solar core, neutrino fluxes, and helioseismic observations can be parametrized and compared. 
Dallas C. Kennedy (University of Florida), Sidney A. Bludman   (University of Pennsylvania)