Helioseismic inferences from the GONG data

Abstract

To accurately measured frequencies of solar oscillations provide a powerful tool to study the solar interior in sufficient detail to test theories of stellar structure and evolution. A primary inversion of these frequencies yields the profiles of sound speed and density throughout the solar interior. Using the seismically inferred sound speed and density profiles alongwith the equations of thermal equilibrium and input physics, it is possible to calculate the temperature and helium abundance profiles inside the sun. The resulting composition profile is essentially flat in the region just below the convection zone indicating the operation of turbulent diffusion in this region. Such a turbulent mixing may explain the observed low Lithium abundance in the solar envelope. These inferred profiles can also be used to test input physics like the equation of state, opacities and nuclear energy generation rates.