\begin{table}%t2 \caption{\label{table_i_eta}Thermal inertia $I$ and beaming factor $\eta$ of asteroid 21 Lutetia derived from the SST data, for two different values of the geometric albedo.} \par %\centerline {\small \begin{tabular}{ccccc} \hline\hline \noalign{\smallskip} &\multicolumn{2}{c}{Nominal value $p_{\rm v}=0.13$$^{\dag}$} &\multicolumn{2}{c}{Extreme value $p_{\rm v}=0.26$$^{\ddag}$} \\ \noalign{\smallskip} $I$ &$\eta$\tablefootmark{a} &$\chi^2$ &$\eta^{a}$ &$\chi^2$\\ (JK$^{-1}$m$^{-2}$s$^{-1/2}$) & &(Jy$^2$) & &(Jy$^2$)\\ \noalign{\smallskip} \hline \noalign{\smallskip} 0 &$0.83\pm0.05$ &69 &$0.78\pm0.05$ &69\\ 10 &$0.76\pm0.05$ &79 &$0.72\pm0.05$ &79\\ 20 &$0.71\pm0.05$ &83 &$0.67\pm0.05$ &83\\ 30 &$0.67\pm0.05$ &84 &$0.63\pm0.05$ &84\\ 40 &$0.64\pm0.05$ &83 &$0.60\pm0.05$ &84\\ 50 &$0.61\pm0.05$ &82 &$0.57\pm0.05$ &81\\ \hline \end{tabular}} \tablefoot{\tablefoottext{a}{The uncertainty of $\pm$0.05 on $\eta$ is obtained by doubling the $\chi^2$ value.}} \vspace{-4mm} \tablebib{$^{\dag}$: Lamy et~al. (\cite{Lamy2010}); $^{\ddag}$: Mueller et~al. (\cite{Mueller2006}).} \vspace{2mm} \end{table}