\begin{table}%t1
\caption{\label{obs_table}The summary of the data set properties for the stars used in this paper. Note that the S/N is calculated at the center of order~60.}
%\centering
\par
\begin{tabular}{lcccccc} 
\hline\hline
\noalign{\smallskip}
 \ \ Target & $\#$ of observations & $\#$ of days with observations &  $\overline{{\rm \# observations/day}}$ & Time span [d]  & $\overline{{\rm S/N}}$ & \\ 
 \hline
Tau~Ceti   & 5270   & 110 & 47.9 & 2308  & 260  \\
$\mu$~Ara & 2868 & 117 &  24.5 & 2303 & 176 \\
$e$~Eri & 1527  & 104 & 14.7 & 2217 & 316 \\
\hline
\end{tabular}
\vspace*{5mm}
\end{table}