\begin{table}%t1
\caption{\label{sn_data}Urumqi data for SN~2008iz at 5~GHz frequency.}
\small%\centerline
 {
\begin{tabular}{cccc}
\hline\hline \noalign{\smallskip}
Observing session & Day & $S_{\rm sn}$ & err \\
 (dd.mm.yyyy)     & (d) & (mJy) & (mJy) \\
\hline
25.02.2008 &   55 &  11 &  9 \\
22.03.2008 &   81 &  19 & 14 \\
22.04.2008 &  112 &  87 & 11 \\
24.05.2008 &  144 & 128 & 27 \\
21.06.2008 &  172 & 157 & 10 \\
18.07.2008 &  199 & 130 & 13 \\
20.08.2008 &  232 & 115 & 13 \\
12.09.2008 &  255 &  95 & 12 \\
13.10.2008 &  286 &  97 & 29 \\
06.11.2008 &  310 &  78 & 13 \\
22.12.2008 &  356 &  60 & 10 \\
11.01.2009 &  376 &  59 & 11 \\
23.02.2009 &  419 &  44 & 10 \\
21.03.2009 &  445 &  45 & 10 \\
19.04.2009 &  474 &  35 & 12 \\
13.05.2009 &  498 &  29 & 11 \\
\hline
\end{tabular}}
\medskip
In Col.~1, the observing date (at half-session); in Col.~2, the corresponding day (0~= January the 1st, 2008).  In Cols.~3 and~4, respectively, the flux density and the error estimations.
\end{table}