\begin{table}%t1
\caption{Observed maser transitions and results of the fits.}\label{tab1}
%\centering
\small
\begin{tabular}{c@{~}cc@{~}c@{~}cc}
\hline
\hline
&&&&&\\[-8pt]
Specie & Transition  & Restoring & $\bar{R}$ & $\triangle{R}$ & Center \\
           &                  &  beam ($mas$\cuad) &($mas$)&($mas$)
&($X_{\rm c}$, $Y_{\rm c}$)\\ 
\hline 
&&&&&\\[-8pt]
 $^{28}$SiO& $v$ = 1 ~~ $J$ = 1--0& 0.78 $\times$ 0.50 & 29.24& 6.42&
(26.9, --21.3)\\
          & $v$ = 1 ~~ $J$ = 2--1          & 0.50 $\times$ 0.50 & 33.84&4.20
&(--35.2, --4.7) \\
	   & $v$ = 2 ~~ $J$ = 1--0          &  0.50 $\times$ 0.50   &25.92 &6.88&
(25.5, --16.3) \\
 $^{29}$SiO& $v$ = 0 ~~ $J$ = 1--0&  0.78 $\times$ 0.22 & one spot &--&--\\
          & $v$ = 0 ~~ $J$ = 2--1          &  non-det. & -- &-- &--\\
\hline
\end{tabular}
\end{table}