The flux of boron-8 neutrinos is highly sensitive to the temperature of the core of the Sun, ϕ ϕ ( B 8 ) ∝ ∝ T 25 . For this reason, a precise measurement of the boron-8 neutrino flux can be used in the framework of the standard solar model as a measurement of the temperature of the core of the Sun. This estimate was performed by Fiorentini and Ricci after the first SNO results were published, and they obtained a temperature of T sun = 15.7 × × 10 6 K ± ± 1 % % from a determined neutrino flux of 5.2×10 /cm ·s.