\begin{table}%t1
\caption{Columns~2 and~3 show the size and the position angle
  of the synthesized beam of the HD~163296 observations performed with
  SMA (at 0.87~mm), PBI (at 1.3~mm and 2.7~mm) and VLA (at
  7~mm). Column~4 show the {\it FWHM} size of the detected emission along
  the major and minor axis of the beam. Column~5 shows the
  integrated flux with the uncertainties due to the statistical  errors.}\label{tab:obs}
%\centering
\small
\begin{tabular}{lllll}
\hline
\hline
$\lambda$ & Beam & & Emission & Flux \\
 (mm) & {\it FWHM} & PA & {\it FWHM} & (mJy)\\
\hline
0.87 & $3\arcsec.14 \times 2\arcsec.21$ & 20\grad & $3\arcsec.60
\times 2\arcsec.64$ & 1910 $\pm$ 20 \\
1.3 & $1\arcsec.95 \times 0\arcsec.42$ &  7\grad & $2\arcsec.01 \times
0\arcsec.83$ & 705 $\pm$ 12  \\
2.8 & $3\arcsec.3 \times 0\arcsec.94$ & 8\grad & $3\arcsec.5 \times
1\arcsec.4$ & 77.0 $\pm$ 2.2  \\
7   & $1\arcsec.71 \times 0\arcsec.81$ & 172\grad & $1\arcsec.71
\times 0\arcsec.94$ & 4.5 $\pm$ 0.5 \\
\hline
 \end{tabular}
\end{table}