\begin{table}%t2
\caption{\label{lines}Summary of the observed lines.}               
  \vspace{-2mm}
   %\centering
\par
\begin{tabular}{c c c c c}        
\hline\hline 
\noalign{\smallskip}              
Transition & Spin & $E\rm _{low}$ [K] & $\nu$ [GHz] & Beam size [$\arcsec$] \\
\hline                        
H$_2^{16}$O~$6_{24}-7_{17}$ & p & 844.2 & 488.491 & 44\\
H$_2^{18}$O~$1_{10}-1_{01}$ & o & 34.3 & 547.676 & 41\\
H$_2^{17}$O~$1_{10}-1_{01}$ & o & 34.3 & 552.021 & 41\\
H$_2^{16}$O~$1_{10}-1_{01}$ & o & 34.3 & 556.936 & 41\\
H$_2^{16}$O~$5_{32}-4_{41}$ & o & 702.0 & 620.701 & 33\\
H$_2^{18}$O~$2_{11}-2_{02}$ & p & 100.7 & 745.320 & 30\\
H$_2^{16}$O~$2_{11}-2_{02}$ & p & 100.9 & 752.033 & 30\\
H$_2^{16}$O~$4_{22}-3_{31}$ & p & 410.6 & 916.172 & 25\\
H$_2^{16}$O~$3_{12}-3_{03}$ & o & 196.9 & 1097.365 & 20\\
H$_2^{18}$O~$1_{11}-0_{00}$ & p & 0.0 & 1101.698 & 20\\
H$_2^{17}$O~$1_{11}-0_{00}$ & p & 0.0 & 1107.167 & 20\\
H$_2^{16}$O~$1_{11}-0_{00}$ & p & 0.0 & 1113.343 & 20\\
\hline                                  
\end{tabular}
 % \vspace{-1mm}
\end{table}