\begin{table}%t1
        %\centering
\par
        \caption{\label{table:systematics}Polarization angle $\alpha_{\rm Sky}$ and polarized
          fraction $\Pi$ computed for different divisions of the data set.}
        \begin{tabular}{lcc}
         \hline\hline\noalign{\smallskip}
        Data subset            & Pol. angle $\alpha_{\rm Sky}$
        & Pol. fraction $\Pi$ 
        \\\hline
        Random 1                & $152.19 \pm 0.36^{\circ}$     & $23.77 \pm 0.52$\% \\
        Random 2                & $152.07 \pm 0.30^{\circ}$     & $23.91 \pm 0.54$\% \\
        \hline
        $\alpha$ scans & $152.02 \pm 0.32^{\circ}$     & $23.38 \pm 0.45$\% \\
        $\delta$ scans           & $152.26 \pm 0.35^{\circ}$     & $24.41 \pm 0.53$\% \\
        \hline
        Night 1                   & $152.47 \pm 0.37^{\circ}$     & $23.96 \pm 0.55$\% \\
        Night 2                             & $151.89 \pm 0.31^{\circ}$     & $23.93 \pm 0.56$\% \\        
        Night 3                             & $152.10 \pm 0.30^{\circ}$     & $23.56 \pm 0.49$\% \\
        \hline
        $\chi_0\in\{-30^\circ,45^\circ \}$                            & $152.17 \pm 0.37^{\circ}$     & $23.60 \pm 0.52$\% \\
        $\chi_0\in\{45^\circ,120^\circ \}$                            & $152.09 \pm 0.30^{\circ}$     & $24.12 \pm 0.55$\%\\
        \hline
        Whole data set                   & $152.13 \pm 0.34^{\circ}$     & $23.84 \pm 0.54$\% \\
        \hline
        \end{tabular}\vspace*{-2mm}
\end{table}