\begin{table}%t2
\caption{\label{tab2}Summary of all relevant maps of SiO maser emission obtained in~R~Aqr.}          %\centering
 \small 
\begin{tabular}{lccccl}     
\hline\hline \noalign{\smallskip}               
Date & Type of  & Axis of symmetry/elongation & Rotation axis & Dominant & Reference  \\       & observation &   PA         &     PA       & half? &  \\  
\hline                        
June 1995 & VLBI & $-$20$^\circ$ & ? & west  & Boboltz et~al.  (\cite{boboltz97}) \\     
Dec. 1995  & VLBI & $-$20$^\circ$ & ? &  & Boboltz et~al. (\cite{boboltz97})  \\     
Feb. 1996  & VLBI & $-$20$^\circ$ & ? &  & Boboltz et~al. (\cite{boboltz97})  \\     
Apr. 1996  & VLBI & $-$20$^\circ$ & ? &  &Boboltz et~al. (\cite{boboltz97})  \\     
Nov. 1996  & conn.\ interf.\ & $\pm$45$^\circ$? & +45$^\circ$ &  
& Hollis et~al. (\cite{hollis00}) \\     
May 1998 & conn.\ interf.\ & $\pm$45$^\circ$? & +45$^\circ$ &
& Hollis et~al. (\cite{hollis00}) \\     
Dec. 1999--Feb. 2000 & conn.\ interf.\ & $\pm$45$^\circ$? & +45$^\circ$ &  
& Hollis et~al. (\cite{hollis00}) \\     
Dec. 2000 & VLBI & $-$40$^\circ$ & $-$40$^\circ$ &  & Hollis et~al. (\cite{hollis01}) \\ 
Jan. 2001 & VLBI & $-$10$^\circ$ & $-$10$^\circ$ &  & Cotton et~al. (\cite{cotton04}) \\ 
Apr. 2001 & VLBI & $-$10$^\circ$? & $-$10$^\circ$ &  & Cotton et~al. 
(\cite{cotton04}) \\ 
Sep. 2004 & VLBI & ~~0$^\circ$    & ~no   & west & Cotton et~al. (\cite{cotton06}) 
\\ 
Dec. 2004 & VLBI & $-$10$^\circ$  & ~no & southwest & this paper \\
Sep. 2005 & VLBI & ~~0$^\circ$   & ~no & north  & this paper \\
Nov. 2005 & VLBI & ~~0$^\circ$   & ~no & north & this paper \\
Dec. 2005 & VLBI & ~~0$^\circ$   & ~no & north & this paper \\
Feb. 2006 & VLBI & ~~0$^\circ$   & ~no & north & this paper \\
Mar. 2006 & VLBI & ~~0$^\circ$   & ~no & north & this paper \\
May 2006 & VLBI & ? & ? & north? & this paper (no astrometry) \\
Jul. 2006 & VLBI & ? & ? & northeast? & this paper (no astrometry) \\
Jul. 2006 & VLBI & ? & ? & northeast? & this paper (no astrometry) \\
Aug. 2006 & VLBI & $-$10$^\circ$ & ? & northeast & this paper \\
Sep. 2006 & VLBI & $-$10$^\circ$ & ~no & northeast & Ragland et~al. (\cite{ragland08}) \\
Oct. 2006 & VLBI & ~~0$^\circ$ & ~no & northeast? & this paper \\
\hline
\end{tabular}
\vspace*{6mm}
\end{table}