\begin{table}%t1
\caption{\label{tab:observations}X-shooter observations of the 8~o'clock arc.}             
%\centering
\small
\begin{tabular}{c c l c c l}     
\hline\hline\noalign{\smallskip}       
 & Observing date & Arm & Resolution                 & Exposure time & Slit position\tablefootmark{a} \\
 &                &     & $R=\lambda/\Delta \lambda$ & (s)           & \\
\hline
\#1 & Nov.~16, 2008 & UV-B  & 4000 & 3600 & ${\rm PA} = 118^{\circ}$ along A2 and A3 \\
\#2 & Nov.~16, 2008 & VIS-R & 6700 & 3600 & Same as \#1 \\
\#3 & Nov.~16, 2008 & UV-B  & 4000 & 3600 & ${\rm PA} = 118^{\circ}$ along A2 and A3 \\
\#4 & Nov.~16, 2008 & VIS-R & 6700 & 3600 & Same as \#3 \\
\#5 & Nov.~18, 2008 & UV-B  & 4000 & 4500 & ${\rm PA} = 121^{\circ}$ along A2 and A3 \\
\#6 & Nov.~18, 2008 & VIS-R & 6700 & 4500 & Same as \#5 \\
\#7 & Nov.~19, 2008 & UV-B  & 4000 & 4500 & ${\rm PA} = 13^{\circ}$ along A2 and the LRG \\	 
\#8 & Nov.~19, 2008 & VIS-R & 6700 & 4500 & Same as \#7\\
\hline                  
\end{tabular}
\tablefoot {\tablefoottext{a}{Labels of the lens images as in \citet{allam07} and Fig.~\ref{fig:acquisition}.}}
\end{table}