\begin{table}%t3
%\centering
\par
\caption{WFPC2 observations. Column 1: quasar name. Column 2: filter. Column 3: proposal P.I. and proposal ID. Column 4: total exposure time  (in ks). \label{obsHST} }
\begin{tabular}{clll}
\hline\hline
Quasar & Band &  P.I and ID& Exp. Time \\
\par
\hline
\ctq&$F555w$  & Falco (9133)   &1 .60 \\
  & $F814w$& Impey (8268) & 2.00\\
 \hline
\heonze& $F814w$ &Surdej (5958) & 1.00\\
\hline
\btreize&$F555w$  & Impey (8268) &5.20 \\ 
&$F814w$ & Impey (8268) & 5.00\\
\hline
\clover& $F814w$ &Turnshek (5621)& 5.20\\ 
\hline
\hevingt&$F555w$ & Falco (8175)  & 1.60\\
 & $F814w$ & Falco (7495) &1.60\\ 
\hline
\par
\end{tabular}
\end{table}