\begin{table}%t3
\caption{\label{properties}Blowout grain size, P-R drag timescales of the debris discs detected in the CSO and/or IRAM surveys. The $\beta$-index discs only for the stars 
with the SED sampled in the submillimetre/millimetre range 
(details in Sect.~4) is reported. }
\par
%\centering
\par
\begin{tabular}{lllllll}
\hline
\hline 
\multicolumn{1}{l}{HD~104860}&
\multicolumn{1}{l}{HD~8907}& 
\multicolumn{1}{l}{HD~377}&
\multicolumn{1}{l}{HD~107146}& 
\multicolumn{1}{l}{HD~61005 }& 
\multicolumn{1}{l}{HD~191089} \\
\hline
$a_{\rm blow,Si}~ [\mu{\rm m}]$&0.64& 0.81 & 0.54 & 0.49& 0.34 & 1.14\\
$t_{\rm P-R,Si}~$ [Myr]& 0.39& 0.5 & 0.03 & 0.08& 9.85 & 1.86\\
 $t_{\rm coll}$ [Myr] & 0.007& 0.007& 0.003& 0.002& 0.009	& 0.005\\
\par
$\beta$&$0.5\pm0.7$&--$0.1\pm1.3$&--&$0.4\pm0.2$&--& --\\
\hline
\end{tabular} 
 \end{table}