\begin{table}%t2
  %\centering
\par
  \caption{Best simultaneous fit of the uniform disk diameters. The reduced $\chi^2$ is defined as the square distance between measure and best fit divided by the difference between number of degrees of freedom and number of measures.\label{tab:fit_contrast}}
  \begin{tabular}[c]{l|cc|c} \hline\hline
     Model    & \object{$\alpha$~PsA}
               & \object{88~Aqr} & $\chi^2$ \\ \hline
                        Previous  &$2.19\pm0.02$& $3.24\pm0.20$ \\
     \#1: Linear $\mu^2_{\rm instru}$ &$2.25\pm0.06$& $3.26\pm0.05$& $1.1$ \\
     \#2: Spline $\mu^2_{\rm instru}$ &$2.23\pm0.07$& $3.26\pm0.06$& $0.51$\\\hline
  \end{tabular}
\end{table}