\begin{table}%[t]%t2
\caption{Spectral indexes and associated spectral types for AB Pic b.}             % title of Table
\label{table:2}      % is used to refer this table in the text
%\centering
                          % used for centering table
\begin{tabular}{c c c c c c c}     % 2 columns
\hline\hline        
\textbf{Index} & H$_{2}$OA & H$_{2}$O--1 & H$_{2}$O--2 & H$_{2}$O & K1 & K2\\         % inserts double horizontal lines
\hline
\textbf{Value} & 0.57 & 0.61 & 0.89 & 1.14 & 0.1 & 0.04 \\
\textbf{Sp. type} & L$2\pm2$ & L$2\pm2$ & L$0\pm2$ & M$9\pm2$& $L_{\rm pec}$ & $L_{\rm pec}$ \\
\hline                                   %inserts single line
\end{tabular}
\end{table}