Inhomogeneity in the solar core

In recent years, normal-mode helioseismology has shown that the spherically averaged sound-speed distribution throughout the solar interior is in rema rkable agreement with suitable standard solar models. This implies that any deviation of the theoretical models from the Sun has only a very small inf luence on the oscillation frequency spectrum (excluding the contributions f rom the uncertain near-surface layers). Nevertheless, it is important to de termine whether the Sun really is very similar to a standard model, or whet her there are substantial differences. This is especially important of the energy-generating core, particularly because it is likely to be necessary t o understand the conditions under which the nuclear reactions are taking pl ace in order to utilize neutrino detectors to the full to measure the prope rties of neutrino transitions.