\begin{table}%T1
  \caption{\label{tab1}Information of the SUMER observations.}
  \small %\centering
\par
  \begin{tabular}{ccccccc}
  \hline \hline\noalign{\smallskip}
Date & Time & Solar X & Solar Y & Detector & slit & Exposure time\\
\hline
1999.03.11   & 01:28-02:25 &($-63^{\prime\prime}$, 67$^{\prime\prime}$)&0$^{\prime\prime}$    &A & 2 &30~s\\ 
1999.03.11   & 12:09-13:09 &($-223^{\prime\prime}$, $ -88^{\prime\prime}$)&280$^{\prime\prime}$  &A & 2 &30~s\\
\hline
\end{tabular}
\end{table}