Narrow Results

Solar oscillations consist of a rich spectrum of internal acoustic waves and surface gravity waves, stochastically excited by turbulent convection. They have been monitored almost continuously over the last ten years with high-precision Doppler images of the solar surface. The purpose of helioseismology is to retrieve information about the structure and the dynamics of the solar interior from the frequencies, phases and amplitudes of solar waves. Methods of analysis are being developed to make three-dimensional images of subsurface motions and temperature inhomogeneities in order to study convective structures and regions of magnetic activity, like sunspots.

It was computed the interior structure and evolution of the Sun with the OPAL equation of state during the hydrogen burning phase. Theoretical evolution calculations of solar model, starting from threshold of stability point at which gravitational and internal energy are nearly the same, were carried out using Ezer equation of state through the gravitational contraction and premain sequence. Later, during hydrogen burning phase, solar model was constructed with OPAL equation of state which was defined in the temperature range 5000 ≤T ≤10⁸K. We compared our solar model with recent models computed by other groups and with helioseismic results.