\begin{table}%t2
  %%\centering

\par
  \caption{Locations and names of the first-guess dust rings.}
  \label{tab_ring_first_guess}
  \begin{tabular}{lcc}
    \hline\hline
    Ring location      & Ring extension [AU] & Name\\
    \hline
    inside d           &  3--15           & ring d \\
    between d and c    & 28--32           & ring cd \\
    between c and b    & 45--60           & ring bc \\
    outside b          & 75--125           & ring b \\
    \hline
  \end{tabular}
\end{table}