\begin{table}%t1
%\centering
\par
\caption{\label{observ}Exposure time, date, and UT of the beginning of each exposure of LHS~2034.}
\begin{tabular}{cccc}
\hline\hline
Spectrum & Date & UT & Exposure \\
     &      &    & time [s]\\
\hline
1st  & March, 14th&01:18:40.0&1200\\
2nd  & March, 14th&01:39:45.0&1200\\
3rd  & March, 14th&02:00:42.0&1200\\
4th  & March, 14th&02:22:33.0&600\\
5th  & March, 14th&02:34:05.0&600\\
6th  & March, 14th&02:45:36.0&600\\
\hline
1th  & March, 16th&00:54:32.0&1200\\
2th  & March, 16th&01:15:30.0&1200\\
\hline
\end{tabular}
\end{table}