\begin{table}%t1
%\centering
\par
\caption{Details of the spectral cameras used.}
\label{referencesystem}
\begin{tabular}{lccc} \hline \hline
Spectral region & Dispersion    & Exposure time & Pixel size \\ 
                &[pm px$^{-1}$] &   [ms]       &   [\arcsec]  \\ \hline
   557.6 nm     &   0.763        &  280--350    & 0.04 \\
   614.9 nm     &   0.887        &  220--300    & 0.04 \\
   709.0 nm     &   1.046        &  160--200    & 0.04 \\
\hline
\end{tabular}
\end{table}