Recent solar neutrino results together with the assumption of a stationary Sun imply severe constraints on the individual components of the total neutrino flux : \Phi _ { Be } \leq 0.7 \cdot 10 ^ { 9 } cm ^ { -2 } s ^ { -1 } , \Phi _ { CNO } \leq 0.6 \cdot 10 ^ { 9 } cm ^ { - % 2 } s ^ { -1 } and 64 \cdot 10 ^ { 9 } cm ^ { -2 } s ^ { -1 } \leq \Phi _ { pp + pep } \leq 65 \cdot 10 ^ { 9 } cm ^ { -2 } s ^ { -1 } ( at 1 \sigma level ) , the constraint on \nu _ { Be } being in strong disagreement with \Phi _ { Be } ^ { SSM } = 5 \cdot 10 ^ { 9 } cm ^ { -2 } s ^ { -1 } .
We study a large variety of non-standard solar models with low inner temperatures , finding that the temperature profiles T ( m ) follow the homology relationship : T ( m ) =k T ( m ) ^ { SSM } , so that they are specified just by the central temperature T _ { c } .
There is no value of T _ { c } which can account for all the available experimental results and also if we restrict to consider just Gallium and Kamiokande results the fit is poor .
Finally we discuss what can be learned from new generation experiments , planned for the detection of monochromatic solar neutrinos , about the properties of neutrinos and of the Sun To appear in “ Solar Modeling Workshop ” , Seattle , March 20-24 , 1994 .