\begin{table}%t6
\caption{\label{table:6}Star catalog for the 2008--2015 Pluto sky path.}
%\centering
\par
\begin{tabular}{c c c c c c c c c}
\hline\hline \noalign{\smallskip}
       Year              & 2008       & 2009     & 2010       & 2011       & 2012       & 2013      & 2014      & 2015      \\
\hline
catalog stars            &   279~127  & 47~576   & 361~830    & 466~433    &  622~436   &  166~283  & 122~199   &  176~495  \\
UCAC2 stars              &   9826    & 7343    & 20~704     & 17~740     &  15~689    &  14~180   & 13~634    &  11~067   \\
2MASS stars              &   155~834  & 32~217   & 121~489    & 167~309    &  155~998   &  109~201  & 78~623    &  72~926   \\
Field stars              &   113~467  & 8016    & 219~637    & 281~384    &  450~656   &  42~902   & 29~942    &  92~502   \\
$\sigma_{\alpha}$ (mas)  &  25        &  27      &  24        &  27        &  25        &  31       &  33       &  30       \\
$\sigma_{\delta}$ (mas)  &  24        &  23      &  22        &  24        &  24        &  36       &  39       &  29       \\
highest $R$ magnitude      &  22.7      & 22.3     &  23.4      &  22.5      &  23.7      &  22.3     &  21.8     &  24.0     \\
$R$ magnitude limit        &  21.0      & 21.0     &  21.5      &  21.0      &  21.5      &  21.0     &  21.0     &  21.5     \\
$R$ magnitude completeness &  9.5--18.5  & 8.5--18.0 &  9.5--18.5  &  10.0--19.0 &  10.4--19.0 &  9.1--18.0 &  8.5--18.0 &  9.4--18.5 \\
\hline
\end{tabular}
\tablefoot {Number of catalog stars per year, position error (estimated from the standard deviation of contributing individual CCD positions about the final catalog star positions), $R$~bandpass magnitude completeness, magnitude limit and highest value.}
\end{table}