1994PASP..106..444T

In a previous paper, Taylor has found that the solar value of (R-I)_c is 0.337 ± 0.0024 mag. This result can be converted to a value of (B-V) by combining it with blanketing corrections and a Hyades color-color relation. The latter are derived and discussed in this paper. The resulting value of (B-V) turns out to be 0.633 ± 0.009 mag. Annoyingly, this datum differs from the mean a number of previous results at better than 99.5% confidence. A survey of the problem reveals a wavelength boundary: H-beta and H-alpha yield the result quoted above, while spectroscopy at wavelengths shortward of H-beta yields (B-V) = 0.665 ± 0.003 mag. The Balmer-line derivations are largely blanketing-insensitive, so for the present, it seems defensible to assume that the Balmer-line result is correct and that its short-wavelength counterparts are affected by some unknown property of the solar blanketing.