\begin{table}%T1
%\centering
\par
\caption{{\it UBVRI} polarimetric observations of Pismis 20.}\label{tab1}
\begin{tabular}{lccccccc}
\noalign{\smallskip}
\hline \hline
\noalign{\smallskip}
\par
 Star$^{a}$  &  Id.$^{b}$ & Filter & $ P_{\lambda}$ & $ \epsilon_{\rm p}$ & $ \theta_{\lambda}$ 
& $ \epsilon_{\theta}$ &  $ n^{c}$ \\
* & & &  \% & \%  & $\degr$ & $\degr$  & \\ 
\par
\noalign{\smallskip}
\hline
\noalign{\smallskip}
\par
 1   &Vz52            &     $U$  & 7.14 &1.13 & 60.3~&~~4.5& 8\\
        &             &     $B$  & 6.79 &0.97 & 61.3~&~~4.0& \\
        &             &     $V$  & 5.64 &0.15 & 60.8~&~~0.7& \\
        &             &     $R$  & 6.02 &0.20 & 62.1~&~~1.0& \\
        &             &     $I$  & 5.41 &0.37 & 64.8~&~~2.0& \\
%        &             &        &     &      &      &     & \\
 2    &Vz72           &     $U$  & 2.80 &0.53 & 45.5~&~~5.5& 6\\
        &             &     $B$  & 4.43 &0.65 & 64.1~&~~2.7& \\
        &             &     $V$  & 5.99 &0.30 & 61.6~&~~1.4& \\
        &             &     $R$  & 6.19 &0.27 & 61.0~&~~1.3& \\
        &             &     $I$  & 4.53 &0.53 & 61.3~&~~3.3& \\
        &             &        &      &     &      &     & \\
 3   &Vz91            &     $U$  & 3.99 &2.32 & 15.3~&~~5.6& 4\\
        &             &     $B$  & 4.28 &2.05 & 10.9~&~~1.3& \\
        &             &     $V$  & 3.18 &0.53 & 63.6~&~~4.7& \\
        &             &     $R$  & 2.97 &0.93 & 58.0~&~~8.7& \\
        &             &     $I$  & 4.31 &1.41 & 64.3~&~~9.1& \\
%        &             &        &      &     &      &     & \\
 4*    &Vz77          &     $U$  & 0.92 &0.23 & 53.9~&~~7.0&12\\
        &             &     $B$  & 2.07 &0.30 & 66.0~&~~4.2& \\
        &             &     $V$  & 1.60 &0.25 & 64.9~&~~4.5& \\
        &             &     $R$  & 1.48 &0.20 & 64.6~&~~3.9& \\
        &             &     $I$  & 1.46 &0.32 & 58.2~&~~6.1& \\
%        &             &        &      &     &      &     & \\
 7    &Vz104          &     $U$  & 2.42 &0.47 & 62.9~&~~5.5& 6\\
        &             &     $B$  & 4.49 &0.42 & 65.4~&~~2.7& \\
        &             &     $V$  & 3.98 &0.35 & 56.7~&~~2.5& \\
        &             &     $R$  & 3.84 &0.35 & 62.8~&~~2.6& \\
        &             &     $I$  & 3.14 &0.58 & 55.2~&~~5.2& \\
 %       &             &        &      &     &      &     & \\
 8    &Vz123          &     $U$  & 4.56 &0.29 & 76.1~&~~1.8& 4\\ 
        &             &     $B$  & 5.77 &0.07 & 62.9~&~~0.3& \\
        &             &     $V$  & 5.79 &0.22 & 61.5~&~~1.1& \\
        &             &     $R$  & 6.05 &0.24 & 62.4~&~~1.1& \\
        &             &     $I$  & 5.14 &0.30 & 61.3~&~~1.7& \\
%        &             &        &      &     &      &     & \\     
 9    &Vz125          &     $U$  & 3.90 &0.28 & 71.0~&~~2.0& 4\\
        &             &     $B$  & 4.84 &0.45 & 64.7~&~~2.6& \\
        &             &     $V$  & 3.76 &0.64 & 61.3~&~~4.9& \\
        &             &     $R$  & 4.92 &0.51 & 64.5~&~~2.9& \\
        &             &     $I$  & 3.80 &0.78 & 61.4~&~~5.8& \\
%        &             &        &      &     &      &     & \\
10    &Vz126          &     $U$  & 6.18 &1.53 & 62.3~&~~7.0& 4\\
        &             &     $B$  & 6.23 &0.30 & 61.7~&~~1.4& \\
        &             &     $V$  & 6.14 &0.34 & 62.6~&~~1.6& \\
        &             &     $R$  & 6.98 &0.12 & 65.2~&~~0.5& \\
        &             &     $I$  & 5.59 &0.22 & 64.8~&~~1.1& \\
%        &             &        &      &     &      &     & \\   
11   &Vz106           &     $U$  & 5.87 &1.46 & 70.5~&~~7.0& 4\\
        &             &     $B$  & 6.11 &0.30 & 62.8~&~~1.4& \\
        &             &     $V$  & 6.17 &0.27 & 66.7~&~~1.2& \\
        &             &     $R$  & 6.25 &0.17 & 65.8~&~~0.8& \\
%        &             &     $I$  & 5.29 &0.35 & 67.8~&~~1.9& \\
\hline
12   &Vz75            &     $U$  &  --  & --  &  -- ~&~~-- & 5\\
        &             &     $B$  &  --  & --  &  -- ~&~~-- & \\
        &             &     $V$  & 3.99 &0.51 & 55.3~&~~3.6& \\
        &             &     $R$  & 3.19 &0.44 & 48.8~&~~3.9& \\
        &             &     $I$  & 2.88 &0.48 & 45.1~&~~4.7& \\
%        &             &        &      &     &      &     & \\
13   &Vz145           &     $U$  & 5.48 &0.21 & 62.6~&~~1.1& 4\\
        &             &     $B$  & 6.70 &0.07 & 60.4~&~~0.3& \\
        &             &     $V$  & 6.29 &0.03 & 60.7~&~~0.1& \\
        &             &     $R$  & 6.49 &0.04 & 61.0~&~~0.2& \\
        &             &     $I$  & 5.55 &0.05 & 60.4~&~~0.3& \\ 
%        &             &        &      &     &      &     & \\ 
 --     &Vz14*        &     $U$  &  --  & --  &  -- ~&~~-- & 3\\   
        &             &      $B$  & 2.04 &0.32 & 59.7~&~~4.7& \\
        &             &      $V$  & 2.36 &0.18 & 59.8~&~~2.1& \\
        &             &      $R$  & 2.45 &0.17 & 55.9~&~~2.0& \\
        &             &      $I$  & 2.72 &0.25 & 59.2~&~~3.1& \\
%        &             &         &      &     &      &     & \\ 
W$R$67    &Vz15         &      $U$  & 6.03 &0.32 & 61.6 &~~1.5& 6\\
        &             &      $B$  & 6.88 &0.23 & 60.0 &~~1.0& \\
        &             &      $V$  & 6.15 &0.07 & 64.2 &~~0.3& \\
        &             &      $R$  & 6.42 &0.11 & 65.5 &~~0.5& \\
        &             &      $I$  & 5.44 &0.12 & 64.1 &~~0.6& \\
%        &             &         &      &     &      &     & \\
 --     &Vz30*        &      $U$  & 1.89 &0.36 & 54.9 &~~5.2& 4\\
        &             &      $B$  & 1.50 &0.31 & 49.3 &~~5.8& \\
        &             &      $V$  & 1.40 &0.18 & 51.9 &~~3.7& \\
        &             &      $R$  & 1.70 &0.17 & 58.3 &~~2.9& \\
        &             &      $I$  & 1.43 &0.09 & 57.6 &~~1.7& \\
 %       &             &         &      &     &      &     & \\
 --     &Vz107*        &      $U$  & 1.25 &0.41 & 79.9~&~~8.8& 1\\
        &              &      $B$  & 1.62 &0.28 & 60.9~&~~4.9& \\ 
        &              &      $V$  & 2.12 &0.14 & 70.6~&~~1.9& \\
        &              &      $R$  & 2.03 &0.13 & 72.2~&~~1.9  \\ 
        &              &      $I$  & 1.19 &0.27 & 72.9~&~~6.5& \\ 
%        &              &         &      &     &      &     & \\
 --     &Vz121         &      $U$  &  --  & --  &  -- ~&~~-- & 3\\
        &              &      $B$  & 3.46 &0.98 & 68.5~&~~7.9& \\
        &              &      $V$  & 4.49 &0.21 & 62.9~&~ 1.3& \\
        &              &      $R$  & 5.17 &0.27 & 64.7~&~~1.5& \\
        &              &      $I$  & 4.37 &0.36 & 66.3~&~~2.3& \\
%        &              &         &      &     &      &     & \\
 --     &Vz128         &      $U$  &  --  & --  & --  ~&~~-- & 3\\
        &              &      $B$  &  --  & --  & --  ~&~~-- & \\
        &              &      $V$  & 3.49 &0.22 & 63.6~&~~1.8& \\
        &              &      $R$  & 4.46 &0.87 & 66.6~&~~5.5& \\
        &              &      $I$  & 4.02 &0.17 & 61.3~&~~1.2& \\
%        &              &         &      &     &      &     & \\
 --     &Vz148         &      $U$  &  --  & --  & --  ~&~~-- &10\\  
        &              &      $B$  &  --  & --  & --  ~&~~-- & \\
        &              &      $V$  & 4.00 &0.23 & 60.5~&~~1.7& \\
        &              &      $R$  & 5.29 &0.31 & 60.3~&~~1.7& \\
        &              &      $I$  & 3.61 &0.44 & 60.2~&~~3.5& \\
\hline
 --     &Vz182         &      $U$  & 4.80 &1.85 & 97.7~&~10.5& 4\\
        &              &      $B$  & 4.93 &1.87 & 85.9~&~~9.2& \\
        &              &      $V$  & 5.67 &0.39 & 56.1~&~~2.0& \\
        &              &      $R$  & 5.44 &0.52 & 61.4~&~~2.7& \\
        &              &      $I$  & 4.89 &1.43 & 55.6~&~~8.2& \\
%        &              &         &      &     &      &     & \\
 --     &Vz183*         &      $U$  &  --  & --  & --   &~~-- & 1\\
        &              &      $B$  & 1.74 &0.37 & 47.1 &~~6.0& \\
        &              &      $V$  & 1.97 &0.21 & 60.3 &~~3.1& \\
        &              &      $R$  & 2.50 &0.20 & 59.5 &~~2.3& \\
        &              &      $I$  & 1.52 &0.44 & 61.4 &~~8.1& \\
\hline
\end{tabular}
\par
\medskip
$ ^{a}$ Lyng\aa~(1986);~* stands for nonmember.\\
$ ^{b}$ V\'azquez et~al.~(1995);~* stands for nonmember.\\
$ ^{c}$ Number of integrations.
\end{table}