\begin{table}%t1
\caption{\label{OM}Effective wavelengths and conversion factors (from count rate to flux) of OM filters.}
\par
%\centering
\par
\begin{tabular}{ccccc}
\hline\hline
  & {{Exp. Time}} & {$\lambda_{\rm  eff}$ } & {{Conversion factor}} & {{Zero point}}\\
  & ks  & {[\AA]} & {[erg cm$^{-2}$ s$^{-1}$ \AA$^{-1}$]}  &\\
\hline 
 {\emph{V}} & {8.8} & {5430} &  {$2.49\times10^{-16}$} &  {17.963}\\
 {\emph{B}} & {4.4} & {4500} & {$1.29\times10^{-16}$} &  {19.266}\\
 {\emph{U}} & {8.0} & {3440} & {$1.94\times10^{-16}$} &  {18.259}\\
 {\emph{UVW1}} & {8.8} & {2910} & {$4.76\times10^{-16}$} &  {17.204}\\
 {\emph{UVM2}}&  {8.8} & {2310} & {$2.20\times10^{-15}$} &  {15.772}\\
 {\emph{UVW2}} & {14.4} & {2120} & {$5.71\times10^{-15}$} &  {14.867}\\
 \hline
\end{tabular}
\end{table}