\begin{table}%t1
\caption{\label{Tab:observations}Summary of observations. From first to last column:
          (1) Revolution and pointing numbers;
          (2) Earth date of the start of the observation in UTC / IJD  (\textit{INTEGRAL} Julian Day = MJD~$-$~51544) / MJD (Modified Julian Day);
          (3) Earth date of the end of the observation in MJD;
          (4)~Individual pointing duration;
          (5) Total IBIS observation time;
          (6) Sum of IBIS Good Time Intervals;
          (7) Total JEM-X1 observation time;
          (8)~Sum of JEM-X1 Good Time Intervals.
          }
%\centering
\par
 \begin{tabular}{l c c c r r r r}
   \hline\hline
       &                                      		     &                    & Pointing  & \multicolumn{2}{c}{IBIS}       & \multicolumn{2}{c}{JEM-X1} \\
   Revolution /    &                              Start date 			&   End date  & duration & Exposure & $\Sigma$ GTIs & Exposure & $\Sigma$ GTIs   \\
   \multicolumn{1}{r}{pointings}& (UTC / IJD / MJD)	&    (MJD)     &  (s)       & (s)        &        (s)~         &   (s)~      &        (s)~           \\
    \hline
    272/75         & 2005-01-06T08:48/1832.36724/53376.36724  &53376.76044 &  42~184    & 42~184 &          30~308 &     36~896 &           36~446 \\
   273/66--81  & 2005-01-08T22:18/1834.92997/53378.92997  &53379.65749 &  3500 & 60~953 &          5~9586 &     60~953 &            56~693 \\
   274/04--09  & 2005-01-10T03:20/1836.13991/53380.13991  &53380.39113 &  3500 & 21~119 &          20~901 &     21~119 &            19~801 \\
    \noalign{\smallskip}
   278/48--74  & 2005-01-23T16:39/1849.69471/53393.69471  &53394.66610 &  2858 & 80~901 &          58~411 &     75~190 &            73~078 \\
    \noalign{\smallskip}
   284/04--45  & 2005-02-09T01:15/1866.05280/53410.05280  &53410.86456 &  3572 & 149~086 &        147~739 &  149~086 &           147~469 \\
   285/02--08  & 2005-02-12T01:02/1869.04402/53413.04402  &53413.23174 &  2200 & 15~517 &           15~349 &    15~517 &            14~394 \\
   286/18--24  & 2005-02-15T10:41/1872.44588/53416.44588  &53416.63218 &  2200 & 15~403 &           15~093 &    15~403 &            15~185 \\
   287/02--08  & 2005-02-18T00:37/1875.02612/53419.02612  &53419.23077 &  2200 & 16~988 &           16~628 &    16~988 &            15~809 \\
   288/02--08  & 2005-02-21T00:25/1878.01820/53422.01820  &53422.25899 &  2200 & 20~101 &           19~226 &    20~101 &            18~854 \\
   \hline
\end{tabular}
\end{table}