LAST HOPE for an astrophysical solution to the solar neutrino problem

We discuss what appears the last hope for an astrophysical solution to the solar neutrino problem: a correlated variation of the astrophysical factors for the helium burning cross sections (S33 and S34) and either S17 or the central temperature Tc. In this context, we recognize the important role played by the CNO neutrinos. In fact, we can obtain a fair fit to the experimental data only if three conditions are met simultaneously: the astrophysical factor S33 is about 200 times what is presently estimated, the astrophysical factor S17 is about 3 times larger and the 13N and 15O neutrino fluxes are negligible compared to the ones predicted by standard solar models. These conditions are not supported by the present data and their correlated combination is improbable.