\begin{table}%t8
\caption{\label{tab:sigma}The uncertainties in the abundances introduced by the
  uncertainties in the atmospheric parameters.}
%\centering
\par
\begin{tabular}{c c c c c c}
\hline\hline
 Elem. & $\sigma_T{_{\rm eff}}$ & $\sigma_{\log g}$ & $\sigma_{\xi}$ &
 $\sigma_{\rm [Fe/H]}$ & $\sigma_{\rm total}$ \\
\hline
Na & $\pm$0.04 & $\pm$0.01 & $\pm$0.02 & $\pm$0.02 & $\pm$0.05 \\
C  & $\pm$0.01 & $\pm$0.02 & $\pm$0.01 & $\pm$0.05 & $\pm$0.06 \\
N  & $\pm$0.03 & $\pm$0.05 & $\pm$0.01 & $\pm$0.03 & $\pm$0.07 \\
O  & $\pm$0.02 & $\pm$0.08 & $\pm$0.01 & $\pm$0.07 & $\pm$0.11 \\
$^{12}$C/$^{13}$C & $\pm$0.00  & $\pm$0.00 &  $\pm$0.00 & $\pm$0.00 & $\pm$0.00 \\
\hline
\end{tabular}
\end{table}