\begin{table}%t5
 \caption{\label{table:Pu_power}Stdev $\sigma_u$ of the unmodeled $1/f$ Stream.}
 %\centering
\small
 \begin{tabular}{cccc}
 \hline\hline
 $\tbase$ & Eq.~(\ref{sigu_apx_num}) & Eq.~(\ref{Pu_power}) &
 Actual \\
           & ($\mu$K) & ($\mu$K) & ($\mu$K) \\
 \hline
 7.5 s   & 115.9 & 103.1 & 121.7 \\
 15 s    & 147.8 & 131.7 & 154.1 \\
 1 min   & 240.0 & 214.4 & 250.3 \\
 1 h     & 1006.0 & 897.3 & 938.0 \\
 \hline
 \end{tabular}
\end{table}