Astrophysical solutions are incompatible with the solar neutrino data.

We consider the most general solar model, using the neutrino fluxes as free parameters constrained only by the solar luminosity, and show that the combined solar neutrino data exclude any astrophysical solution at 98% C.L. Our best fit to the 7 Be and 8 B fluxes is respectively <7% and 37±4% of the standard solar model prediction, but only with a large χ 2 (5.6 for 1 d.f.). This best fit to the fluxes contradicts explicit nonstandard solar models, which generally reduce the 8 B flux more than the 7 Be. Those models are well parameterized by a single parameter, the central temperature.