Iron core in the sun?



A suggestion has been made that the sun may have a central core composed of iron (New Scientist, June 23, 1983). This suggestion is the latest attempt to force a fit to theoretical models of the sun's internal temperature structure. That the sun does not fit well enough as a model for compositional origin of the rest of the solar system is evidenced in its apparent deficiency in the production of neutrinos. Measurements on the earth to detect the emission of solar neutrinos are typically low by as much as a factor of 3. If the core of the sun were to be composed of a sufficiently stable element, such as the form of iron that would exist at 14 million K, the production of neutrinos would be about what is observed. The result of the calculations of Carl Rouse is that the sun could have a core radius of about 5% of the total, with a density of about 1.6×105 kg m−3. This core would be consistent with the properties of an iron plasma, instead of hydrogen and helium nuclei. In the modeling procedure one could adjust the sun's temperature to a value lowered by about 1 million K and have a lowered neutrino flux as well.