\begin{table}%t3
%\centering
\par
\caption{\label{Negative}Negative detections.}
\begin{tabular}{l l c l l l }
\hline \hline\noalign{\smallskip}
\multicolumn{1}{c}{Asteroid} &
\multicolumn{1}{c}{Date} &
\multicolumn{1}{c}{$\Delta t$} &
\multicolumn{1}{c}{Exp}       &
\multicolumn{1}{c}{$\Delta m$} &
\multicolumn{1}{c}{$D$} \\
\multicolumn{1}{c}{} &
\multicolumn{1}{c}{         } &
\multicolumn{1}{c}{  [h]    } &
\multicolumn{1}{c}{  [s]    } &     
\multicolumn{1}{c}{ [mag]   } &
\multicolumn{1}{c}{ [km]    }\\
\hline
2007 KE$_{1}$  & 2007-08-08/09 & 1.0 & 10 & 0.1 & 0.145 \\
               & 2007-08-09/10 & 1.1 & 10 & 0.1 &       \\
2007 PD$_{8}$  & 2007-09-04/05 & 0.8 & 15 & 0.2 & 0.092 \\
2004 HZ        & 2007-04-12/13 & 0.3 & 30 & 0.1 & 0.106 \\
2007 RH$_{1}$  & 2007-09-05/06 & 0.5 & 10 & 0.15& 0.090 \\
               & 2007-09-06/07 & 0.5 & 10 & 0.15& 0.090 \\
2007 GY$_{1}$  & 2007-04-15/16 & 0.5 & 15 & 0.1 & 0.030 \\
2007 VH$_{184}$& 2007-11-16/17 & 0.5 & 10 & 0.15& 0.124 \\
               & 2007-11-17/18 & 0.5 & 10 & 0.15& 0.124 \\
2007 EK$_{88}$ & 2007-03-27/28 & 0.7 & 20 & 0.15& 0.149 \\  
2007 CQ$_{5}$  & 2007-04-09/10 & 1.7 & 15 & 0.20& 0.112 \\
               & 2007-05-08/09 & 0.5 & 15 & 0.20&       \\
2007 CO$_{26}$ & 2007-03-16/17 & 1.5 & 10 & 0.15& 0.156 \\
               & 2007-03-18/19 & 1.5 & 30 & 0.1 & 0.156 \\ 
\hline 
\end{tabular}
\tablefoot{$\Delta t$ is the time span covered by observations, Exp gives the time of a single exposure, $\Delta m$ is the recorded magnitude range, and $D$ stands for the  effective diameter.}
\end{table}