\begin{table}%t2
%\centering
\par
\caption{\label{TOBS}Exposure details: (1)  observation ID; (2) exposure number used in Table~\ref{TSCR}.} 
\begin{tabular}{lccclc}
\hline\hline
Target      & Obs. ID$^{(1)}$ & Exp. No.$^{(2)}$ & Camera & Start date and time & End date and time \\
            &                 &          &        &  [UT]   & [UT] \\   
\hline   
PG~1001+054 & 0150610101 & 1 & pn    & 2003-05-04 at 14:51:02 & 2003-05-04 at 17:45:52 \\ 
            &            & 2 & MOS 1 & 2003-05-04 at 14:27:34 & 2003-05-04 at 17:45:32  \\
            &            & 3 & MOS 2 & 2003-05-04 at 14:27:34 & 2003-05-04 at 17:45:37 \\
            &            & 4 & OM    & 2003-05-04 at 11:16:53 & (exposure time: $5000 ~\rm s$) \\
            &            & 5 & OM    & 2003-05-04 at 12:45:20 & (exposure time: $3000 ~\rm s$) \\
PG~2112+059 & 0150610201 & 6 & pn    & 2003-05-14 at 15:33:10 & 2003-05-14 at 19:51:46 \\
            &            & 7 & MOS 1 & 2003-05-14 at 15:10:39 & 2003-05-14 at 19:51:26 \\
            &            & 8 & MOS 2 & 2003-05-14 at 15:10:39 & 2003-05-14 at 19:51:31 \\
            &            & 9 & OM    & 2003-05-14 at 15:15:17 & (exposure time: $5000 ~\rm s$) \\ 
PG~1535+547 & 0150610301 & 10 & pn    & 2002-11-03 at 01:28:48 & 2002-11-03 at 09:20:44 \\
            &            & 11 & MOS 1 & 2002-11-03 at 01:06:17 & 2002-11-03 at 09:20:24 \\
            &            & 12 & MOS 2 & 2002-11-03 at 01:06:17 & 2002-11-03 at 09:20:24 \\
\hline 
\end{tabular}
\end{table}