\begin{table}%t2
\caption{\label{tabella2}Magnitudes of VLBL candidates from our observational campaign; the error associated to the $B$ and $R$~filters is 0.05~mag.}
%\centering
\small
\begin{tabular}{cccccccccc}
\hline\hline\noalign{\smallskip}
Source  & Julian date & $B$ mag & $R$ mag & $J$ mag & err & $H$ mag & err & $K$ mag & err \\
\hline
\a      &  2~453~387.5  & 18.15 & 17.11 &       &     &       &     &       &     \\
        &  2~453~465.5  & 18.72 & 17.67 & 15.97 & 0.05& 15.18 & 0.07& 14.26 & 0.09\\ 
        &  2~453~738.5  & 18.56 & 17.75 &       &     &       &     &       &     \\ 
        &  2~453~796.5  & 18.44 & 17.43 &       &     &       &     &       &     \\ 
        &  2~453~823.5  & 18.55 & 17.53 &       &     &       &     &       &     \\ 
\hline
\b      &  2~453~387.5  & 18.67 & 17.83 &       &     &       &     &       &     \\ 
        &  2~453~437.5  & 17.31 & 16.56 &       &     &       &     &       &     \\ 
        &  2~453~466.5  & 17.73 & 16.96 & 15.26 & 0.04& 14.44 & 0.06& 13.36 & 0.07\\
        &  2~453~738.5  & 17.82 & 17.23 &       &     &       &     &       &     \\
        &  2~453~796.5  & 18.43 & 17.60 &       &     &       &     &       &     \\
\hline
\c      &  2~453~387.5  & 19.71 & 18.64 &       &     &       &     &       &     \\      
        &  2~453~465.5  & 19.48 & 18.32 & 16.66 & 0.03& 15.75 & 0.05& 14.51 & 0.05\\    
        &  2~453~738.5  & 19.43 & 18.33 &       &     &       &     &       &     \\     
        &  2~453~822.5  & 19.59 & 18.40 &       &     &       &     &       &     \\      
\hline
\d      &  2~453~387.5  & 19.57 & 18.21 &       &     &       &     &       &     \\      
        &  2~453~439.5  & 18.98 & 17.72 &       &     &       &     &       &     \\      
        &  2~453~466.5  & 19.38 & 18.06 & 16.41 & 0.07& 15.45 & 0.14& 14.55 & 0.16\\      
        &  2~453~738.5  & 18.52 & 17.26 &       &     &       &     &       &     \\       
        &  2~453~823.5  & 17.96 & 16.79 &       &     &       &     &       &     \\      
        &  2~453~823.5  &       & 16.77 &       &     &       &     &       &     \\      
\hline
\e      &  2~453~557.5  &       & 17.08 &       &     &       &     &       &     \\ 
        &  2~453~415.5  & 19.06 & 17.86 &       &     &       &     &       &     \\       
        &  2~453~796.5  & 18.66 & 17.51 &       &     &       &     &       &     \\       
        &  2~453~885.5  & 18.56 & 17.52 &       &     &       &     &       &     \\      
\hline
\f      &  2~453~466.5  & 20.09 &       &       &     &       &     &       &     \\ 
        &  2~453~466.5  & 20.04 & 18.65 & 16.85 & 0.05& 16.06 & 0.08& 14.71 & 0.08\\     
        &  2~453~497.5  & 19.94 & 18.55:&       &     &       &     &       &     \\      
        &  2~453~796.5  & 21.06:& 19.40:&       &     &       &     &       &     \\                       &  2~453~823.5  &       & 19.35 &       &     &       &     &       &     \\ 
        &  2~453~915.5  & 20.11 & 18.71 &       &     &       &     &       &     \\      
\hline
BZB~J1927+6117      &  2~453~498.5  & 17.72 & 17.22 &       &     &       &     &       &     \\   
        &  2~453~527.5  & 17.78 & 17.24 & 15.80 & 0.02& 14.95 & 0.03& 13.96 & 0.03\\ 
        &  2~453~557.5  & 17.78 & 17.24 &       &     &       &     &       &     \\   
        &  2~453~565.5  & 17.79 & 17.24 &       &     &       &     &       &     \\   
        &  2~453~579.5  & 17.91 & 17.33 &       &     &       &     &       &     \\   
        &  2~453~643.5  & 17.86 & 17.32 &       &     &       &     &       &     \\   
        &  2~453~885.5  & 17.69 & 17.08 &       &     &       &     &       &     \\   
        &  2~453~915.5  & 17.80:& 17.26 &       &     &       &     &       &     \\   
        &  2~453~981.5  & 17.92 & 17.33 &       &     &       &     &       &     \\   
        &  2~453~982.5  & 17.95 & 17.34 &       &     &       &     &       &     \\   
        &  2454015.5  & 17.67:& 17.34 &       &     &       &     &       &     \\   
        &  2454051.5  & 18.00 & 17.39 &       &     &       &     &       &     \\   
\hline
\l      &  2~453~527.5  &       & 18.87 & 17.17:& 0.03& 15.58 & 0.03&       &     \\
        &  2~453~738.5  & 20.03 &       &       &     &       &     &       &     \\
        &  2~453~915.5  &       & 19.25 &       &     &       &     &       &     \\
        &  2~453~981.5  & 20.51 & 19.30 &       &     &       &     &       &     \\  
        &  2~453~982.5  & 20.71 & 19.30 &       &     &       &     &       &     \\   
\hline
\end{tabular}
\end{table}