\begin{table}%t1
\caption{\label{table1}Journal of observations.}
%\centering
\par
\begin{tabular}{cccc}
\hline \hline \noalign{\smallskip}
HCG & Telescope \& & Exp. time & Obj. scan \\
  &   date of observation  & (hours)& wavelength (\AA) \\
\hline
2ab & ESO Sep. 2000  & 1.2 & 6657 \\
2c & ESO Sep. 2000  & 0.9 & 6657  \\
7ad  & ESO Sep. 2000  & 1.5 & 6655 \\
7bd  & ESO Sep. 2000  & 0.9 & 6655  \\
22bc & ESO Sep. 2000  & 1.1 & 6621 \\
37a & CFHT March 2000 & 2.1 & 6710 \\
37d & CFHT March 2000 & 2.1 & 6710 \\
40 & CFHT March 2000 & 1.9  & 6709 \\
47 & CFHT March 2000 & 2.3  & 6771 \\
49 & CFHT March 2000 & 2.3  & 6780 \\
54 & CFHT March 2000 & 1.9  & 6594  \\
56 & CFHT March 2000 & 2.3  & 6747  \\
68ab & CFHT March 2000 & 1.9  & 6613 \\
68c & CFHT March 2000 & 1.9  & 6616 \\
79 & CFHT Aug. 1996 & 1.2 & 6661  \\
93ac & CFHT Aug. 1996 & 1.2 &  6675 \\
93b & CFHT Aug. 1996 & 1.2  & 6665  \\
\hline
\end{tabular}
%\vspace*{3mm}
\end{table}