\begin{table}%t1
%\centering
\par
\caption{Dates and geometric data (range) of the observations.
\label{tabdatgeo}}
\begin{tabular}{lcccr}\hline\hline
Teles.  & $r_{\rm h}$(AU) &  $\Delta$ (AU) &  $\alpha$(deg)
 & Observing dates \\ \hline
%&&&&\\
OSN    &   51.92  &  51.26--51.19   & 0.82  & 1, 2, 6, 8 Feb. 06\\
OSN    &   51.93  &  51.08--51.07   & 0.57  & 1, 2 Mar. 06\\
OSN    &   51.93  &  51.15--51.18   & 0.70  & 7, 8, 10, 12 Apr. 06\\
OSN    &   51.97  &  51.99--51.91   & 1.09  & 14--18 Dec. 06\\
CAHA   &   51.98  &  51.58--51.52   & 0.98  & 11--16 Jan. 07\\
\hline 
\end{tabular}
\end{table}