**Table 1:** Photospheric parameters of the sample stars.
$\begin{displaymath}\begin{tabular}{lr@{$~\pm~$}lr@{$~\pm~$}l}% \hline\hline & \... ...umber) & 0.005 & 0.0005 & 0.035 & 0.005\\ \hline \end{tabular}\end{displaymath}$

	1 Introduction
	2 Model calculations
	3 Testbed for non-LTE spectrum synthesis
	4 Spectral energy distribution
	5 Conclusions
	References