\begin{table}%t1
\caption{\label{Tab:Obs}Details of the imaging observations used in this work.}
\vspace*{-2mm}
%\centerline
 {
\begin{tabular}{cccccc}
\hline\hline\noalign{\smallskip}
Date & $\lambda_{\rm central}$ & $\Delta\lambda$ & $N$\tablefootmark{a} & NDIT\tablefootmark{b} & DIT\tablefootmark{c}\\
 &  [$\mu$m]  &   [$\mu$m] &  & & [s] \\
\hline
29 April 2006 & 1.66 & 0.33 & 32 & 28 & 2  \\
29 April 2006 & 2.18 & 0.35 & 32 & 28 & 2 \\
26 May 2008 & 3.80 & 0.62 & 202 & 150 & 0.2\\
\hline
\end{tabular}}
\tablefoot{
\tablefoottext{a}{Number of (dithered) exposures.}
\tablefoottext{b}{Number of integrations that were averaged on-line by the read-out
  electronics.}
\tablefoottext{c}{Detector integration time. The total integration time of each observation amounts to $N\times{\rm NDIT} \times{\rm DIT}$.}}
\vspace*{-2mm}
\end{table}