\begin{table}%t1
%\centering
\par
\caption {\label{tab:observations}A list of campaigns where TNOs were found.}
\begin{tabular}{cccccc}
\hline\hline
\noalign{\smallskip}
$\Omega$ [deg$^2$] &	N 	& $m_{50}$	&	$\epsilon$ [${}^{\circ}$]&$\alpha$ [${}^{\circ}$]	& Reference\\
\hline 
0.7	&	2	&	23.5	&	$0.42$	&$0.84$&        \cite{Irwin-et-al-1995}$^\star$	\\
1.2	&	7	&	24.85	&	$0.55$	&$1.1$&		\cite{Jewitt-et-al-1995}	\\
3.9	&	12	&	24.2	&	$0.99$	&$1.97$&	\cite{Jewitt-et-al-1996}$^\star$	\\
4.4	&	3	&	23.2	&	$1.05$	&$2.1$&		\cite{Jewitt-et-al-1996}$^\star$	\\
0.35	&	1	&	24.6	&	$0.30$	&$0.59$&	\cite{Gladman-et-al-1998}	\\
0.049	&	4	&	25.6	&	$0.11$	&$0.22$&	\cite{Gladman-et-al-1998}$^\star$	\\
0.075	&	0	&	25	&	$0.14$	&$0.27$&	\cite{Gladman-et-al-1998}	\\
51.5	&	13	&	23.4	&	$3.6$	&$7.2$&		\cite{Jewitt-et-al-1998}	\\
0.01	&	2	&	27.94	&	$0.05$	&$0.1$&		\cite{Chiang-Brown-1999}	\\
20.2	&	3	&	23.6	&	$2.25$	&$4.5$&		\cite{Trujillo-et-al-2000}	\\
1.5	&	24	&	24.9$\dots$ 25.9&$0.61$	& $1.22$&	\cite{Allen-et-al-2001}$^\star$	\\
0.012	&	0	&	26.7	&	$0.06$	&$0.11$&	\cite{Gladman-et-al-2001}$^\star$	\\
0.31	&	17	&	25.93	&	$0.28$	&$0.56$&	\cite{Gladman-et-al-2001}$^\star$	\\
73	&	86	&	24.0	&	$4.25$	&$8.5$&		\cite{Trujillo-et-al-2001a}$^\star$	\\
164	&	3	&	21.1	&	$6.40$	&$12.8$&	\cite{Trujillo-et-al-2001b}$^\star$	\\
5108	&	19	&	20.7 	&	$10$	&$255.4$&	\cite{Trujillo-Brown-2003}$^\star$	\\
0.02	&	3	&	28.7	&	$0.07$	&$0.14$&	\cite{Bernstein-et-al-2004}$^\star$	\\
550	&	183	&	22.5	&	$5$	&$55$&		\cite{Elliot-et-al-2005}$^\star$	\\
8000	&	1 big	&	20$\dots$21&	$10$	&$400$&	 	\cite{Larsen-et-al-2007}$^\star$	\\
3.0	&	70	&	26.4	&	$0.87$	&$1.73$&	\cite{Fraser-et-al-2008}	\\
2.8	&	82	&	25.7	&	$1.67$	&$1.67$&	\cite{Fuentes-Holman-2008}	\\
0.255	&	20	&	26.76	&	$0.25$	&$0.5$& 	\cite{Fuentes-et-al-2009}	\\
0.33	&	36	&	26.8	&	$0.29$	&$0.57$&	\cite{Fraser-Kavelaars-2009}	\\
\hline
\end{tabular}
\tablefoot{The sky area covered ($\Omega$),
the number of the objects discovered ($N$),
the limiting magnitude~($m_{50}$),
an estimated half-opening angle~$\epsilon$,
and the ecliptic longitude coverage~$\alpha$
are given.
Papers that provide enough data for objects discovered in 
that survey to identify them in the MPC database
are marked with an asterisk.}
\end{table}