\begin{table}%t3 \caption{\label{tabSpectraDistances}Properties of the different central stars.} %\centerline { \begin{tabular}{l l l l l l} \hline\hline \noalign{\smallskip} Name & Type & $T_{\rm eff}$ (K) & $d$ (pc) & $a$ (AU)\\ \hline \noalign{\smallskip} $\sigma \ {\rm Bootis}$\tablefootmark{a,b} & F2V & 6722 & 15.5 & 1.89\\ Sun\tablefootmark{c} & G2V & 5777 & 0 & 1.0\\ $\epsilon \ {\rm Eridani}$\tablefootmark{a,d} & K2V & 5072 & 3.2 & 0.61 & \\ AD Leo\tablefootmark{e,f} & M4.5V & 3400 & 4.9 & 0.15\\ \hline \noalign{\smallskip} \end{tabular}} \par \tablefoot{\tablefoottext{a}{\citet{Habing2001};} \tablefoottext{b}{\citet{Cenarro2007};} \tablefoottext{c}{\citet{CoxAstroQuant};} \tablefoottext{d}{\citet{Santos2004};} \tablefoottext{e} {\citet{Leggett1996};} \tablefoottext{f}{\citet{Segura05}.}} \end{table}