\begin{table}%t1
\caption{\label{tab1}The basic parameters and observational data of sample stars.  }
%\centering
\par
\begin{tabular}{rlrcccrcccc}
  \hline\hline
  {\rm No.} &  {\rm Star} & $V$ &  $b-y$ & $m_1$  &$c_1$ &~$\pi$(mas) &~$\sigma$($\pi$) &{\rm Obs. date}&{\it S/N}  \\
  \hline
1  & {\rm HD}~108177 & 9.66 &  0.331 & 0.060 & 0.285 & 10.95 & 1.29 & 2001/04/25 & 260  \\
2  & {\rm HD}~149414 & 9.60 &  0.474 & 0.202 & 0.159 & 20.71 & 1.50 & 2001/04/17 & 218  \\
3  & {\rm BD}~+02$^{\circ}$3375 & 9.94 &  0.352 & 0.047 & 0.258 & 8.35 & 1.64 & 2001/04/17 & 263  \\
4  & {\rm BD}~+20$^{\circ}$3603 & 9.77 &  0.323 & 0.048 & 0.308 & 6.47 & 7.85 & 2001/04/16 & 218  \\
5  & {\rm BD}~+26$^{\circ}$2606 & 9.73 &  0.332 & 0.052 & 0.289 & 10.28 & 1.42 & 2001/04/17 & 240  \\
6  & {\rm BD}~+28$^{\circ}$2137 & 10.89 &  0.322 & 0.055 & 0.321 & 5.35 & 1.94 & 2001/04/23 & 240  \\
7  & {\rm BD}~+29$^{\circ}$2091 & 10.26 &  0.382 & 0.059 & 0.157 & 10.55 & 1.75 & 2001/04/18 & 170  \\
8  & {\rm BD}~+34$^{\circ}$2476 & 10.05 & 0.309 & 0.055 & 0.354 & 5.37 & 1.60 & 2001/04/17 & 260  \\
9  & {\rm BD}~+42$^{\circ}$2667 & 9.86 & 0.342 & 0.067 & 0.277 & 8.05 & 1.12 & 2002/04/24 & 207  \\
10 & {\rm BD}~+51$^{\circ}$1696 & 9.91 & 0.398 & 0.099 & 0.179 & 13.61 & 1.54 & 2001/04/21 & 170  \\
            \hline
         \end{tabular}
   \end{table}