\begin{table}%t2
\caption{\label{opt}$R$-band observations of the optical afterglow of GRB~061122 from the MDM telescope.}
%\centering
\par
\begin{tabular}{lccc}
\hline\hline
  Date (UT)    &      Time (UT)   & $T - T_0$ (s)   &   $R_{\rm mag}$ \\
\hline
 Nov. 23   &   01:52   &    17.9  &   22.61 $\pm$ 0.05\\
 Nov. 24   &   02:26   &    42.5  &   23.41 $\pm$ 0.15\\
\hline
\end{tabular}
\end{table}