\begin{table}%t12
\caption{\label{tab:systematic_uncertainties}Summary of the systematic uncertainties affecting the
calibrated magnitudes and fluxes.}
%\centering
\small
\begin{tabular}{lcccc}
\hline
\hline 
                         & $g_M$  & $r_M$  & $i_M$ & $z_M$ \\
\hline 
Aperture corrections                   & ${<}0.001$  & ${<}0.001$ &  ${<}0.001$    &   ${<}0.001$       \\
Background subtraction                 & ${<}0.001$  & ${<}0.001$ &  $\pm 0.005$ &   ${<}0.001$       \\
Shutter precision                      & $\pm 0.0015$ & $\pm 0.0015$ & $\pm 0.0015$  & $\pm 0.0015$ \\
Linearity                              & ${<}0.001$  & ${<}0.001$ &  ${<}0.001$    &   ${<}0.001$       \\
Second order airmass corrections       & ${<}0.001$  & ${<}0.001$  & ${<}0.001$ &  ${<}0.001$           \\
Grid Reference Colors                  & ${<}0.001$  & ${<}0.001$  & ${<}0.001$ &  ${<}0.001$           \\
Grid Color Corrections                 & ${<}0.001$  & ${<}0.001$  & $\pm 0.002$ & ${<}0.001$         \\
Landolt catalog                        & $\pm 0.001$ & $\pm 0.001$ & $\pm 0.001$ & $\pm 0.002$  \\
Magnitudes of \bdtruc                  & $\pm 0.002$ & $\pm 0.004$ & $\pm 0.003$ & $\pm 0.018$  \\
\hline
Total                                  & $\pm 0.003$ & $\pm 0.004$ &  $\pm 0.006$  &  $\pm 0.018$    \\
\hline
SED of \bdtruc                            & $\pm 0.001$ & $\pm 0.002$ &  $\pm 0.004$  &  $\pm 0.007$    \\
\hline 
Total                                  & $\pm 0.003$ & $\pm 0.005$ &  $\pm 0.007$  &  $\pm 0.019$    \\
\hline 
\end{tabular}
%\vspace*{5mm}
\end{table}