\begin{table}%t1
\caption{\label{tab_obs}Observational circumstances for the observations of 21 Lutetia with the SST on 10 and 11 December 2005.}
%\centerline
{\small
\begin{tabular}{lcccccc} 
\hline\hline
\noalign{\smallskip}
Target [set]  & Date & UT$_{\rm start}$ &  UT$_{\rm end}$ & $r$ & $\Delta$ & $\alpha$  \\
      &  &  (hh:mm:ss)    & (hh:mm:ss)    & (AU)  & (AU) & ($^{\circ}$)   \\  
\hline
\noalign{\smallskip}
Lutetia [01] & 10 Dec. & 17:32:45  & 17:36:11 & 2.8102330 & 2.6573956 & 21.12 
\\
Lutetia [02] & 10 Dec. & 18:28:06  & 18:31:32 & 2.8102551 & 2.6568463 & 21.13 
\\
Lutetia [03] & 10 Dec. & 19:01:37  & 19:05:03 & 2.8102661 & 2.6565717 & 21.13 
\\
Lutetia [04] & 10 Dec. & 19:44:44  & 19:48:10 & 2.8102826 & 2.6561597 & 21.13 
\\
Lutetia [05] & 10 Dec. & 20:18:06  & 20:21:33 & 2.8102935 & 2.6558849 & 21.13 
\\
Lutetia [06] & 10 Dec. & 21:07:53  & 21:11:19 & 2.8103101 & 2.6554730 & 21.13 
\\
Lutetia [07] & 10 Dec. & 21:37:15  & 21:40:41 & 2.8103211 & 2.6551983 & 21.13 
\\
Lutetia [08] & 10 Dec. & 22:25:30  & 22:28:56 & 2.8103431 & 2.6546488 & 21.13 
\\
Lutetia [09] & 10 Dec. & 23:07:46  & 23:11:13 & 2.8103540 & 2.6543741 & 21.13 
\\
Lutetia [10] & 10 Dec. & 23:40:07  & 23:43:33 & 2.8103705 & 2.6539620 & 21.13 
\\
Lutetia [11] & 11 Dec. & 00:28:35  & 00:32:01 & 2.8103869 & 2.6535499 & 21.13 
\\
Lutetia [12] & 11 Dec. & 01:05:54  & 01:09:20 & 2.8103979 & 2.6532752 & 21.13 
\\
Lutetia [13] & 11 Dec. & 01:41:51  & 01:45:17 & 2.8104144 & 2.6528631 & 21.13 
\\
Lutetia [14] & 11 Dec. & 02:23:52  & 02:27:18 & 2.8104308 & 2.6524509 & 21.13 
\\
\hline
\end{tabular}}
\tablefoot{$r_{\rm h}$, $\Delta$: Distances from Lutetia to respectively the Sun and the SST;
$\alpha$: solar phase angle as seen from the SST.}\vspace*{-3mm}
\end{table}