\begin{table}%t2
%\centering
\par
\caption {\label{table:2}Numerical results for the weighted fits of periodic nutation terms (i.e 18.6-yr and 9.3-yr) plus secular and constant term for the LLR series.} % title of Table
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 % used for centering table
\begin{tabular}{c r r} % centered columns (4 columns)
\hline\hline % inserts double horizontal lines
Terms & $DX$ (mas) & $DY$ (mas) \\ % table heading
\hline % inserts single horizontal line
sin (18.6-yr) & $ 0.171\pm 0.273$  & $ 0.075\pm 0.255$ \\ % inserting body of the table
cos (18.6-yr) & $ 0.121\pm 0.144$ & $-0.241\pm 0.143$ \\ 
sin (9.3-yr)  & $ 0.121 \pm 0.163$   & $ 0.104\pm 0.154$ \\
cos (9.3-yr)  & $ 0.315\pm 0.139$ & $-0.009 \pm 0.131$ \\
secular term (mas/cy) & $3.516 \pm 3.841$ & $-0.155 \pm 3.662$ \\
constant term & $0.163 \pm 0.153$ & $-0.220 \pm 0.145$ \\
\hline %inserts single line
\end{tabular}
\end{table}