\begin{table}%t1
\caption{Observed objects.}\label{Tab1}
\small%\centerline
 {
\begin{tabular}{rcccccccccl}
\hline \hline
&&&&&&&&&& \\[-8pt]
 NSER      & RA(2000)   & Dec(2000)    & $B_J$  & $F$     &nv$^a$&SA57X$^b$ &ni$^c$&$z$&nz$^d$& classification$^e$ \\
\hline
  681      & 13 08 05.91& +29 06 53.5  & 19.955 &   19.261  & EV & --    &   & 0.403  &c  & BLAGN \\
 2688      & 13 09 42.82& +29 11 24.7  & 22.280 &   20.868  & EV & --    &   & 0.401  &   & NELG \\
 3873      & 13 09 36.84& +29 13 23.9  & 22.345 &   21.503  & EV & --    &   & 0.298  &   & NELG \\
 4326      & 13 08 53.67& +29 14 06.1  & 20.867 &   20.172  & EV & --    &   & 0.216  &   & NELG \\
 5334      & 13 09 44.08& +29 15 47.0  & 22.235 &   21.249  & EV & --    &   & 0.298  &e  & NLAGN \\
 6825      & 13 08 22.19& +29 18 07.8  & 22.920 &   21.262  &    & 37   &   & 0.437  &   & NELG \\
 6884      & 13 08 13.52& +29 18 12.5  & 20.833 &   19.006  &    & 38   &   & 0.275  &a  & XBONG \\
 7726      & 13 08 34.17& +29 19 27.0  & 21.446 &   20.409  & EV & --    &   & 0.405  &   & NELG \\
 8553      & 13 07 13.93& +29 20 42.1  & 20.946 &   19.675  & EV & --    &   & 0.297  &a, c& NELG \\
 8890      & 13 08 55.51& +29 21 10.5  & 20.964 &   19.051  &    & 61   &   & 0.330  &a& galaxy \\
 9342      & 13 08 56.78& +29 21 50.5  & 20.885 &   19.140  &    & 66   & A & 0.246  &   & NLAGN \\
 9820      & 13 08 56.74& +29 22 29.0  & 21.868 &   20.097  &    & 71   & M & 0.355  &a  & XBONG \\
10144      & 13 09 00.18& +29 22 58.9  & 20.180  &   18.471  &    & 81   &   &  -     &   & star \\
10459      & 13 09 34.63& +29 23 28.1  & 21.366 &   19.682  & EV & --    &   & 0.324  &a, c& galaxy \\
10953      & 13 08 50.34& +29 24 15.0  & 20.960 &   20.071  &    & 90   & A & 0.148  &   & NELG \\
12399      & 13 09 51.62& +29 26 17.9  & 21.930 &   20.710  & PV & --    &   & 0.424  &   & NELG \\
12472      & 13 07 29.20& +29 26 25.4  & 22.578 &   20.933  &    & 102  &   & 0.094  &e, u& galaxy \\  
13310      & 13 07 56.71& +29 27 38.0  & 21.656 &   21.074  &    & 109  & M & 2.530  &e  & BLAGN \\
13571      & 13 09 49.30& +29 28 00.7  & 21.713 &   20.677  & EV & --    &   & 0.317  &   & NELG \\
13732      & 13 08 24.04& +29 28 19.2  & 22.763 &   22.640  &    & 115  &   & 0.671  &e, u& BLAGN \\
14260      & 13 07 58.37& +29 29 08.2  & 22.223 &   20.718  & EV & --    &   & 0.248  &a, u& galaxy\\
14264      & 13 08 03.40& +29 29 08.8  & 20.391 &   18.782  & EV & 120  &   & 0.286  & & NLAGN \\
15465      & 13 09 17.09& +29 31 04.3  & 21.886 &   21.151  & PV & 127  &   & 0.528  &e  & BLAGN \\
16338      & 13 07 30.34& +29 32 22.5  & 22.719 &   21.957  & EV & --    &   & 0.252  &e  & NLAGN \\
16710      & 13 09 03.87& +29 33 06.3  & 21.690 &   20.119  & EV & --    &   & 0.440  &u  & NELG \\
17475      & 13 07 53.14& +29 34 17.0  & 22.551 &   22.410  & PV & --    &   & 0.555  &e, u& BLAGN \\
\hline
\end{tabular}}
\medskip
$^a$ Notes on variability selection. EV: extended variable; PV: pointlike variable. \\
$^b$ X-ray catalogue number following \citet{trev07}. \\
$^c$ Notes on optical identification. M: marginal; A: ambiguous. \\
$^d$ Notes on redshift. e: only emission; a: only absorption; c: confirmed redshift (see BTK); u: uncertain.\\ 
$^e$ BLAGN: broad line AGN; NLAGN: narrow line AGN; NELG: narrow emission line galaxy;
XBONG: X-ray bright optically normal galaxy; galaxy: galactic spectrum with only absorption lines.
\end{table}