\begin{table}%t1
\par
    \caption{\label{tab:sources}Source list.}
%\centerline
 {
%\small 
\begin{tabular}{lcccl}
 \hline \hline
Source  & RA & Dec & $V_{\rm LSR}$ & $n$(H$_2$)$^a$ \\
 & (2000) & (2000) & (\kms ) & (cm $^{-3}$)\\
\hline \noalign{\smallskip}
Barnard 1b  & 03:33:20.9 & 31:07:34  & 6.8 & $3 \times 10^6$ \\
NGC1333-IRAS4A  & 03:29:10.5  & 31:13:31 & 7.2 & $2 \times 10^6$ \\
NGC1333-DCO$^+$   & 03:29:12.3  & 31:13:25 & 7.2 &  $1 \times 10^6$\\
L1544 & 05:04:16.6  &   25:10:48 & 7.4 &  $2 \times 10^6$\\ 
L134N(S)  & 15:54:08.6 & $-$02:52:10 & 2.4 & $2 \times 10^6$ \\
L1689N  & 16:32:29.5 & $-$24:28:53 & 3.8 &   $2 \times 10^6$ \\
\hline
\end{tabular}
}
\smallskip
$^a$ From Caselli et~al. \cite{caselli08}.
\end{table}