ABSTRACT
Our knowledge of the Sun's interior, hidden under the opaque photosphere, has been traditionally derived from only the theoretical models based on the global properties of the Sun. Solar standard models have been constructed based on theoretical formulations and numerical methods. This chap-ter discusses the basic equations of solar structure, and gives a brief introduction of the procedures for calculating solar models. Energy production in the central core, and its transport through the ra-diative and convective zone in solar interior are described. Some concepts such as the Schwarz-schild criterion for the onset of convection, mixing length and convective overshoot are discussed. Detection of solar neutrinos produced in the hot and dense central core provides an important tool to infer about the solar interior. It was suggested to use the neutrinos as a probe of solar interior, and a tool to test the reliability of solar standard models. However, there were early set-backs due to observational deficiency as compared to the predicted neutrino flux from solar standard models; the so-called, neutrino problem. This chapter describes the series of experiments that have led to even-tual resolution of neutrino problem, vindicating the standard solar models, and establishing that neu-trinos have finite, non zero-mass, and possess the strange ability to transform among three flavours.
