\begin{table}%tB.3 \caption{\label{PM52_h2:tab}Proper Motions in HH~52 and HH~53 -- H$_2$.} \small%\centerline { \begin{tabular}{ccccccccccc} \hline\hline Knot ID & \multicolumn{3}{c}{$\alpha$(2000.0)} & \multicolumn{3}{c}{$\delta$(2000.0)} & PM & PA & $v_{\rm tan}$ & Filter \\ & \multicolumn{3}{c}{($^{\rm h}$$^{\rm m}$$^{\rm s}$)} & \multicolumn{3}{c}{($\degr$ $\arcmin$ $\arcsec$)} & ($\arcsec$~yr$^{-1}$) & ($\degr$) & (km~s$^{-1}$) \\ \hline HH~52~B2/B3 &12&55&05.0&--76&57&54 & 0.026 $\pm$ 0.004$^{a}$ & 40 $\pm$ 9 & 22 $\pm$ 4$^{a}$ & H$_2$ \\ HH~52~B5/B6 &12&55&02.7&--76&57&57 & 0.041 $\pm$ 0.014$^{b}$ & 281 $\pm$ 12 & 35 $\pm$ 12$^{b}$ & H$_2$ \\ HH~52~C1 &12&55&05.4&--76&58&01 & 0.008 $\pm$ 0.004$^{b}$ & 51 $\pm$ 26 & 7 $\pm$ 3$^{b}$ & H$_2$ \\ HH~53~A &12&55&15.4&--76&57&30 & 0.016 $\pm$ 0.003 & 298 $\pm$ 15 & 14 $\pm$ 3 & H$_2$ \\ HH~53~B &12&55&14.5&--76&57&31 & 0.007 $\pm$ 0.003$^{b}$ & 231 $\pm$ 34 & 6 $\pm$ 3$^{b}$ & H$_2$ \\ HH~53~C &12&55&16.5&--76&57&30 & 0.010 $\pm$ 0.003 & 270 $\pm$ 26 & 9 $\pm$ 2 & H$_2$ \\ HH~53~H &12&55&15.2&--76&57&26 & 0.024 $\pm$ 0.004 & 27 $\pm$ 8 & 21 $\pm$ 4 & H$_2$ \\ \hline \end{tabular}} \medskip Notes: $^{a}$~mean value, variable in velocity, see text and Table~\ref{acc:tab}; $^{b}$~below 3$\sigma$.\\ \end{table}