\begin{table}%t7
\caption{Membership and photometry of Per~OB2. We first list the 29
objects observed by us (cf.\ Table~\ref{tab:1}). Below the horizontal
line, we added two classical members from B52 that were not observed
(Sect.~\ref{subsec:B52}) and three members from Z99 for which
literature radial velocities exist
(Sect.~\ref{subsubsec:extra}). Columns:
(1) HD number;
(2) spectral type;
(3) classical membership assignment (B52; C: certain member; P:
    possible member; N: non-member);
(4) Hipparcos membership (Z99);
(5) membership based on radial velocity (mostly this work);
(6) final membership, based on Cols.~4 and~5; in the case labeled
    with an asterisk, also photometric information was used;
(7)~Johnson $B$ magnitude (from Tycho);
(8) Johnson $V$ magnitude (from Tycho); and
(9) visual extinction $A_V$ from Str\"omgren or Johnson photometry
    (Sect.~\ref{subsec:cmd}).
We do not list photometric data for eight clear non-members
(Sect.~\ref{subsec:cmd}). Membership for the run-away star $\xi$~Per
(HD~24912) comes down to semantics; we have indicated it by the label~R.}
%%\centering
\par
\begin{tabular}{rlccccrrr}
\hline\hline
HD & SpT & \multicolumn{4}{c}{Membership} & $B$ & $V$ & $A_V$\\
(1) & (2) & (3) & (4) & (5) & (6) & (7) & (8) & (9)\\
\hline
 18830& A0       &  & C& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 19216& B9V      &  & P& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 19567& B9       &  & C& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 20113& B8       &  & P& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 20987& B2V      &  & C& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 21483& B3III    & P& N& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 21856& B1V      & C& N& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 5.816&  5.899&  0.569\\
 22114& B8Vp     &  & P& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 22951& B0.5V    & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 4.927&  4.975&  0.737\\
 23060& B2Vp     & C& P& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 7.585&  7.531&  1.072\\
 23180& B1III    & P& P& N& \phantom{$^\ast$}N\phantom{$^\ast$}& 3.871&  3.855&  0.886\\
 23268& A0       &  & C& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 23478& B3IV...  & C&  & C& \phantom{$^\ast$}C\phantom{$^\ast$}& 6.717&  6.688&  0.783\\
 23597& B8       &  & C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 8.262&  8.225&  0.795\\
 23625& B2.5V    & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 6.598&  6.564&  0.852\\
 23802& B5Vn     &  & C& P& \phantom{$^\ast$}P\phantom{$^\ast$}& 7.555&  7.386&  1.029\\
 24012& B5       &  & C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 7.835&  7.850&  0.632\\
 24131& B1V      & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 5.747&  5.784&  0.737\\
 24190& B2V      & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 7.458&  7.449&  0.936\\
 24398& B1Ib     & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 2.966&  2.883&  1.158\\
 24583& B7V      &  & P& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 9.047&  9.002&  0.626\\
 24640& B1.5V    & C& P& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 5.431&  5.489&  0.563\\
 24970& A0       &  & P& C& \phantom{$^\ast$}N$^\ast$& 7.589&  7.466&  0.643\\
 25539& B3V      & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 6.873&  6.874&  0.762\\
 25799& B3V...   & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 7.066&  7.032&  0.802\\
 25833& B5V:p    & C& C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 6.710&  6.720&  0.571\\
 26499& B9       &  & C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 9.205&  9.057&  1\phantom{.000}\\
278942& B3III    &  & C& P& \phantom{$^\ast$}P\phantom{$^\ast$}&10.307&  9.175&  4.750\\
281159& B5V      & C& P& P& \phantom{$^\ast$}P\phantom{$^\ast$}& 9.278&  8.681&  2.720\\
\hline
 24534& O9.5pe   & C&  & P& \phantom{$^\ast$}P\phantom{$^\ast$}& 6.862&  6.793&  1.569\\
 24912& O7.5Iab: & P& N& N& \phantom{$^\ast$}R\phantom{$^\ast$}& 4.022&  4.042&  0.859\\[5pt]
 20825& G5III    &  & C& N& \phantom{$^\ast$}N\phantom{$^\ast$}&      &       &       \\
 23244& A0       &  & C& P& \phantom{$^\ast$}P\phantom{$^\ast$}&      &       &       \\
281157& B3V      &  & C& C& \phantom{$^\ast$}C\phantom{$^\ast$}& 9.811&  9.177&  2.930\\
\hline
\end{tabular}
\label{tab:7}
\end{table}