The Internal Temperature-Density Distribution of the Sun.

An accurate determination has been made of the internal temperature-density distribution of the sun, using the point-convective model. Account is taken of the variation of the guillotine factor throughout the star in contrast to all previous calculations on this model. The hydrogen content is adjusted so that the radiative envelope fits onto the convective core, where all the energy production is assumed to take place. The integration is started from the surface of the sun, and it turns out that a hydrogen content of 35 per cent by weight gives a good fitting of envelope to core, whereas hydrogen contents of 40 or 30 per cent give obvious lack of fitting in opposite senses. The interface occurs at a distance outward from the center equal to 12 per cent of the total radius. The central temperature is 25.7 106 degrees C, and the central density i io g/cm3. While the hydrogen content ~ per cent) agrees with the value found with the Eddington standard model, the central temperature and central density are considerably higher than the corresponding Eddington values. If the energy source varies as the seventeenth power of the temperature-a dependence indicated by the astrophysical data and present theories of energy pro- duction, then the convective core contributes 98 per cent of the total luminosity. This justifies the use of the point-convective model. Possible improvements in the calculation are discussed