MU-LEONIS - THE BRANCH-BONNELL-TOMKIN METALLICITY REVISED

Recently, Taylor has established an [Fe/H] zero point for K giants. Taylor's work permits a reassessment of the well-known mu Leo metallicity of Branch, Bonnell & Tomkin (BBT). Correction to the new zero point lowers the BBT result from +0.48 to +0.35 dex, with the correction being significant at about 97% confidence. It is also possible to set an upper limit on sigma-BBT, the standard deviation of the uncorrected BBT datum. This limit turns out to be 0.17 dex at 95% confidence. Given these results, the corrected datum yields a lower limit at 95% confidence which may be as small as [Fe/H] = 0.12 dex. The BBT result is therefore not decisive evidence for supermetallicity in K giants.