\begin{table}%t7
\caption{\label{table4d}Isotopic ratios in CN at various nucleocentric distances. The C/2002~T7 (LINEAR) data include spectra taken at up to 180~000~km but are strongly weighted for the range $24~000{-}45~000$~km.}
%\centering
\small
\begin{tabular}{llll} 
\hline \hline
&&& \\[-8pt]
Comet &Distance& $^{12}$C/$^{13}$C &  $^{14}$N/$^{15}$N  \\
&(km)\\
\hline  
C/2001 Q4 (NEAT) &$0{-}3000$&$             90\pm 20 $&$ 135 \pm 25 $\\
C/2001 Q4 (NEAT) &$25~000$&$              95\pm 20 $&$ 135 \pm 25 $\\
C/2001 Q4 (NEAT) &$50~000$&$              90\pm 20 $&$ 145 \pm 25 $\\
C/2002 T7 (LINEAR) &$0{-}2000$&$      85\pm 20 $&$ 155 \pm 25$\\
C/2002 T7 (LINEAR) &$24~000{-}180~000$&$      80\pm 25 $&$ 165 \pm 30$\\
\hline
\end{tabular}
\end{table}