\begin{table}%t2
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\par
%\begin{minipage}[t]{\linewidth}
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\caption{\label{tab2}Standard stars\tablefootmark{b}.}  
\begin{tabular}{c c c c c c c }     
\hline\hline                  
 &Star&$P$($\%$)&PA ($^{\circ}$)&$P_{\rm obs}$($^{\circ}$)&PA$_{\rm obs}$($^{\circ}$)&$\theta$$_{0}$ ($^{\circ}$)\\
\hline                    
IGO&GD319&0.09 $\pm$ 0.09&140&0.6 $\pm$ 0.3&113&27 $\pm$ 10\\
December&C191B2B&0.09 $\pm$ 0.06&157&0.2 $\pm$ 0.1&131& \\
2008&HD25443&5.13 $\pm$ 0.06&134&4.0 $\pm$ 0.5&111&  \\
 &HD94851&0.06 $\pm$ 0.02&NA&0.2 $\pm$ 0.1&22.5& \\
 &HD251204&4.04 $\pm$ 0.07&147&2.4 $\pm$ 1.1&117& \\
 \\
 OHP&GD319&0.09 $\pm$ 0.09&140&0.06 $\pm$ 0.05&134& $-4  \ \pm  \ 10$\\
 March&HD251204&4.04 $\pm$ 0.07&147&4.4 $\pm$ 0.2&153\\
 2009&HD155197&4.38 $\pm$ 0.03&103&4.2 $\pm$ 0.15&117\\
  &HD155197&4.38 $\pm$ 0.03&103&3.9 $\pm$ 0.4&118\\
  \\
  IGO&HD94851&0.06 $\pm$ 0.02&NA&0.33 $\pm$ 0.08&67&0 $\pm$ 10\\
  April-&HD147084&4.46 $\pm$ 0.03&32&4.17 $\pm$ 0.2&42\\
  May&HD155197&4.38 $\pm$ 0.03&103&4.57 $\pm$ 0.07&95\\
 2009&HD155197&4.38 $\pm$ 0.03&103&4.43 $\pm$ 0.07&94\\
\hline                  
\end{tabular}
 \tablefoot{\tablefoottext{b}{Polarization $P$ and position angle PA for the literature values. $P_{\rm obs}$ and PA$_{\rm obs}$ for the measurements. The chosen values for PA$_{\rm obs}$ are the closest to the expected ones. NA = not available.}}
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\end{table}