\begin{table}%T1 \par \caption{\label{table1}General properties of the studied objects and sources of the UV data.} \small%\centerline { \begin{tabular}{lllccc} \hline\hline & \multicolumn{3}{c} {Central star$^{a,b}$} & Diam.$^{c}$ &Log total \\ \cline{2-4} \rule[-0.5ex]{0pt}{3ex} Object (PN G) & $m_V$ & Spec. type & $T_*$(kK) & ($''$)& $I(\rm H\beta)^{(2)}$ \\ \hline PB~8 (292.4+04.1) & 13.8 & [WC~5$-$6] & 58 & 5~ & $-$11.41 \\ NGC~2867 (278.1$-$05.9) & 15.7 & [WO~2] & 155 & 14~ & $-$10.58 \\ PB~6 (278.8+4.9) & 17.6 & [WO~1] & 158 & 11~ & $-$11.87 \\ \hline \end{tabular}} \smallskip $^{a}$ Stellar magnitude and stellar type temperature as given by \citet{ackerneiner03}.\\ $^{b}$ Temperature from Todt et al. (in preparation).\\ $^{c}$ Nebular diameter and total H$\beta$ flux from \citet{ackeretal92}. \end{table}