fitting of individual metal lines for abundance determinations. However, the spectra allow a determination of an overall abundance value. The general metallicity of the models was varied until an optimum fit was achieved. Since the extinction towards these high Galactic latitude targets is low we do not expect the Ca H and K lines to be significantly contaminated by interstellar absorption. However, by including these lines we obtain an upper limit to the metallicity. The spectral ranges used for determining the metallicity contain a mix of spectral features, but the dominant species is Fe I. We thus expect our metallicity \[Met/H\] to be an approximate indicator of iron abundance.

We show the results of our fits in Table 2 and the best fits to the spectra in Figure \[spec-fit\]. The best-fit temperature of our sources are in the range [$T_{\mathrm{eff}}$]{}=7200–7900K. Although the metal abundance is less well constrained, each source has a metallicity less than solar at the 1$\sigma$ level and for all but one source this is also true at the 3$\sigma$ level. Fixing $\log g$ at 3.5 and 4.5 rather than 4.0 changes the temperature by less than 90K and $\log g$ by less than 0.1 dex.

(8,6) 