\begin{table}%t11
\caption{\label{tab:catalog}Content of the \object{NGC~6253} catalog.}
%\centering
\small
\begin{tabular}{c l}
\hline \hline
 Col.  1 & Sequential identification number\\
 Col.  2 & $x$ coordinate in the CCD reference system (Col. 28)\\
 Col.  3 & $y$ coordinate in the CCD reference system (Col. 28)\\
 Col.  4 & Right Ascension (J2000)\\
 Col.  5 & Declination (J2000)\\
 Col.  6 & Calibrated $B$ magnitude\\
 Col.  7 & Error in $B$ magnitude\\
 Col.  8 & Calibrated $V$ magnitude\\
 Col.  9 & Error in $V$ magnitude\\
 Col. 10 & Calibrated $R$ magnitude\\
 Col. 11 & Error in $R$ magnitude\\
 Col. 12 & Calibrated $I$ magnitude\\
 Col. 13 & Error in $I$ magnitude\\
 Col. 14 & Calibrated $J$ magnitude\\
 Col. 15 & Error in $J$ magnitude\\
 Col. 16 & Calibrated $H$ magnitude\\
 Col. 17 & Error in $H$ magnitude\\
 Col. 18 & Calibrated $K$ magnitude\\
 Col. 19 & Error in $K$ magnitude\\
 Col. 20 & $J$ magnitude from 2MASS\\
 Col. 21 & $H$ magnitude from 2MASS\\
 Col. 22 & $K$ magnitude from 2MASS\\
 Col. 23 & Relative proper motion in Right Ascension (mas/year)\\
 Col. 24 & Error in RA proper motion\\
 Col. 25 & Relative proper motion in Declination (mas/year)\\
 Col. 26 & Error in Dec proper motion\\
 Col. 27 & Membership probability\\
 Col. 28 & CCD number in the system of MPG/ESO WFI\\
\hline
\end{tabular}
\end{table}