\begin{table}%t2
\caption{Optical imaging observations.}\label{imaging}
%\centering
\par
\begin{tabular}{lllllcl}
\hline
\hline
Run & Telescope    & Instrument & Time span  & CCD   & Pixel size  & No. of pixels    \\
    &              &            & [yrs]      &       & [$\arcsec$] &                  \\
\hline
I1  & NTT 3.5 m     & EFOSC~2   & 1989       & \#05  & 0.2578      & $512\times 320$  \\
I2  & ESO 3.6 m     & EFOSC~1   & 1989--1991 & \#08  & 0.3375      & $1024\times 640$ \\
I3  & ESO 3.6 m     & EFOSC~1   & 1991--1993 & \#26  & 0.6094      & $512\times 512$  \\
I4  & ESO/MPI 2.2 m & EFOSC~2   & 1991       & \#05  & 0.3500      & $512\times 320$  \\
I5  & ESO/MPI 2.2 m & EFOSC~2   & 1991       & \#19  & 0.3340      & $1024\times 1024$\\
I6  & Danish 1.5 m  & DFOSC      & 1996       & Loral & 0.3800      & $2052\times 2052$\\
\hline
\end{tabular}
\end{table}