The sensitivity of the seismic solar model to Newton's constant

Abstract

New experimental determinations of Newton’s gravitational constant have been recently given. There are significant disagreements between these new measurements. We show that the high accuracy obtained with current standard solar models is such that the uncertainties in core temperature profiles arising from the uncertainties in G can be comparable to the range in predictions by the solar standard model of the observed acoustic modes and solar neutrino fluxes. Solar models that have been computed with a relatively high value of Newton’s constant, in agreement with the new measurements, produce an increase in the predicted sound speed and density profiles, with significant changes in the solar structure within the central region. These solar models predict a value of the active 8 B neutrino flux slightly closer to the Sudbury Neutrino Observatory and Super-Kamiokande measurements than the value obtained with the previous solar standard model (with G from CODATA 1986). Furthermore, we find that solar models with G between 6.65 × 10 −8 and 6.685 × 10 −8 cm 3 g −1 s −2 will have a reasonable agreement with the seismic solar model. Current uncertainties in solar physics and opacities prevent any stronger conclusions at present. However, we may be able potentially to use the Sun to determine an independent value of Newton’s constant, representing an alternative measurement to the value that is determined in Earth laboratories.