\begin{table}%t1
\caption{Field O stars in newly detected clusters. The asterisk indicates that
the star is found in a region with star formation signposts (see
Sect.~\ref{youth}). In Col.~2 we give the visual multiplicity~(VM) of the stars,
adopted from~M98 and~G87; VMS~= Visual Multiple Star. In Col.~3 we use the
following abbreviations for the spectroscopic multiplicity~(SM): C~= constant radial
velocity, SB1~= single-lined spectroscopic binary, SB2~= double-lined
spectroscopic binary. Addition of an "O'' and/or "E'' indicates that the orbit is 
known and/or an eclipsing system. A colon indicates uncertainty.}\label{sfreg}
%\centering
\par
  \begin{tabular}{lccccc}
\hline
\hline
Name & VM & SM & $I_{\rm C}$ & Radius  & $\log(\rho_{\rm I_{C}})$\\
     &            &             &           &    (pc) & ($\rm stars~pc^{-3}$) \\
\hline
HD~52266$^{*}$   & single & SB1? & $4\pm2$  & 0.10 & $2.0\pm1.0$ \\
HD~52533$^{*}$   & VMS    & SB1O & $15\pm5$ & 0.30 & $2.5\pm0.9$  \\
HD~57682         & single & C    & $4\pm5$  &  --   & -- \\
HD~153426        & single & SB2: & $5\pm4$  &  --   & --\\
HD~195592$^{*}$  & single & SB1? & $18\pm3$ & 0.25 & $2.6\pm0.8$ \\
\hline
 \end{tabular}
\end{table}