\begin{table}%t4
\caption{Envelope morphology in  light.\label{tab4}}
\small
%\centerline
{        \begin{tabular}{llrrlr}
        \noalign{\smallskip}
        \hline
	\hline
        \noalign{\smallskip}
Star & Env.$^a$ & $\theta_{\rm env}$ & $\tau_{\rm env}$ & Core$^a$ & $\tau_{\rm c}$ \\
     &    &  $(\arcsec)$  & (yr)   & & (yr) \\       
\noalign{\smallskip}
\hline
\noalign{\smallskip}
\noalign{\smallskip}
\object{IRC+10216}       &  C s & 200 &  8700 & Bp     & 50 \\
\object{IRC+10011}       & C s? &  40 &  6800 & Bp     & 75 \\
\object{CIT 6}           & ? s? &  25$^b$& 3200$^b$ & Bp     & 40  \\
\object{AFGL 2155}       &  ?   &  18 &  5700 &$\ldots$  & \\
\object{OH~348.2$-$19.7}& C    &  28 & 12900 & C      & \\
\object{AFGL 2514}       & E    &  40 &  7700 & E      & \\
\object{AFGL 3068}       & Sp   &  42 & 15200 & Sp     & \\
\object{AFGL 3099}       & ?    &  20 & 12200 &$\ldots$& \\
\object{AFGL 3116}       & ?    &  18 &  5600 &$\ldots$& \\
\hline
\end{tabular}}
\par
\smallskip
{\small $^a$ Morphology: C~=~circular, s~=~shells, E~=~elliptical, 
Sp~=~spiral, Bp~=~bipolar. $^b$ Based on CO.}  
\par
\end{table}