\begin{table}%tb2
\caption{\label{indubv}All-sky \ubv\ photometry of \oca with known times of observations.
Note that for observations by \citet{haupt74} the Julian dates are only
known to 1 decimal digit and should not be used for the analysis of
rapid variations.}
%%\centering

\small
\begin{tabular}{lcccc}
\hline\hline\noalign{\smallskip}
   HJD  & $V$ & $B-V$ & $U-B$ &Source\\
$-2~400~000$&     &       &       &      \\
\hline\noalign{\smallskip}
38~295.8415&  4.467& $-0.065$& $-0.533$&   \citet{john66} \\
38~298.9317&  4.524& $-0.059$& $-0.526$&        \arcsec         \\
38~310.7859&  4.518& $-0.056$& $-0.529$&        \arcsec         \\
40~452.6000&  4.63 & $-0.08$ & $-0.52$ &   \citet{haupt74}\\
40~458.6000&  4.59 & $-0.07$ & $-0.53$ &        \arcsec         \\
\hline
\end{tabular}
\end{table}