\begin{table}%tC.1 \caption{\label{acc:tab}Accelerated Motions in HH~52, HH~53, and HH~54 -- H$\alpha$, [\ion{S}{ii}] and H$_2$~-- parameters derived from the quadratic fit.} \small%\centerline { \begin{tabular}{cccccccc} \hline\hline %&&&&&&& \\[-8pt] Knot ID & $P_{a}$($\chi^2/\nu$) & PM & Accelerated motion & PA($\vec{v}$) & PA($\vec{a}$) & Filter & Note\\ & $\times$100 (\%) & ($\arcsec$~yr$^{-1}$) & ($\arcsec$~yr$^{-2}$) & ($\degr$) & ($\degr$) & & Reliable \\ \hline HH~52~A5 & 0.10 & 0.071 $\pm$ 0.012 & 0.0067 $\pm$ 0.0013 & 110 $\pm$ 8 & 133 $\pm$ 11 & [\ion{S}{ii}] & no \\ & 1.00$^a$ & 0.137 $\pm$ 0.086$^b$ & 0.018 $\pm$ 0.008$^b$ & 5 $\pm$ 33 & 340 $\pm$ 26 & H$\alpha$ & \\ HH~52~B1 & 0.05 & 0.132 $\pm$ 0.017 & 0.0226 $\pm$ 0.0018 & 116 $\pm$ 8 & 299 $\pm$ 5 & [\ion{S}{ii}] & yes \\ & 1.00$^a$ & 0.093 $\pm$ 0.068$^b$ & 0.02 $\pm$ 0.01$^b$ & 111 $\pm$ 20 & 285 $\pm$ 16 & H$\alpha$ & \\ HH~52~B2 & 0.99 & 0.099 $\pm$ 0.021 & 0.0060 $\pm$ 0.0021$^b$ & 7 $\pm$ 11 & 12 $\pm$ 23 & [\ion{S}{ii}] & yes \\ & 1.00 & 0.131 $\pm$ 0.023 & 0.0109 $\pm$ 0.0027 & 9 $\pm$ 16 & 16 $\pm$ 23 & H$\alpha$ & \\ HH~52~B3 & 0.34 & 0.122 $\pm$ 0.017 & 0.0121 $\pm$ 0.0019 & 112 $\pm$ 7 & 128 $\pm$ 9 & [\ion{S}{ii}] & no \\ HH~52~B2/B3 & 1.00$^a$ & 0.194 $\pm$ 0.077$^b$ & 0.061 $\pm$ 0.015 & 357 $\pm$ 22 & 348 $\pm$ 23 & H$_2$ & no \\ HH~52~B4 & 0.22 & 0.124 $\pm$ 0.016 & 0.0134 $\pm$ 0.0019 & 90 $\pm$ 6 & 94 $\pm$ 7 & [\ion{S}{ii}] & no\\ HH~52~B5 & 0.05 & 0.106 $\pm$ 0.041$^b$ & 0.0117 $\pm$ 0.0030 & 243 $\pm$ 13 & 238 $\pm$ 13 & [\ion{S}{ii}] & no\\ & 0.10 & 0.146 $\pm$ 0.045 & 0.0076 $\pm$ 0.0052$^b$ & 202 $\pm$ 12 & 215 $\pm$ 36 & H$\alpha$ & \\ HH~52~B8 & 1.00 & 0.164 $\pm$ 0.067$^b$ & 0.020 $\pm$ 0.007$^b$ & 290 $\pm$ 16 & 291 $\pm$ 19 & [\ion{S}{ii}] & yes \\ HH~52~C1 & 0.05 & 0.052 $\pm$ 0.012 & 0.0105 $\pm$ 0.0014 & 69 $\pm$ 13 & 229 $\pm$ 10 & [\ion{S}{ii}] & yes\\ HH~52~C4 & 0.28 & 0.144 $\pm$ 0.025 & 0.0105 $\pm$ 0.0018 & 347 $\pm$ 7 & 338 $\pm$ 11 & [\ion{S}{ii}] & yes\\ & 1.00$^a$ & 0.166 $\pm$ 0.047 & 0.0163 $\pm$ 0.0050$^b$ & 348 $\pm$ 14 & 338 $\pm$ 21 & H$\alpha$ & \\ HH~52~D4 & 0.18 & 0.073 $\pm$ 0.014 & 0.0038 $\pm$ 0.0013$^b$ & 33 $\pm$ 9 & 16 $\pm$ 21 & [\ion{S}{ii}] & no \\ & 0.53 & 0.093 $\pm$ 0.050$^b$ & 0.011 $\pm$ 0.0050$^b$ & 12 $\pm$ 22 & 347 $\pm$ 28 & H$\alpha$ \\ HH~53~A & 0.93 & 0.034 $\pm$ 0.012$^b$ & 0.0040 $\pm$ 0.0012 & 230 $\pm$ 18 & 197 $\pm$ 20 & [\ion{S}{ii}] & no \\ HH~53~B & 0.96 & 0.038 $\pm$ 0.022$^b$ & 0.0047 $\pm$ 0.0012 & 332 $\pm$ 18 & 343 $\pm$ 18 & [\ion{S}{ii}] & no \\ HH~53~G & 0.07 & 0.039 $\pm$ 0.013 & 0.0049 $\pm$ 0.0014 & 104 $\pm$ 16 & 212 $\pm$ 18 & [\ion{S}{ii}] & no\\ & 1.00$^a$ & 0.212 $\pm$ 0.069$^b$ & 0.0276 $\pm$ 0.0089 & 105 $\pm$ 15 & 113 $\pm$ 18 & H$\alpha$ \\ HH~54~B$_1$& 0.34 & 0.04 $\pm$ 0.01 & 0.0088 $\pm$ 0.0024 & 40 $\pm$ 12 & 61 $\pm$ 15 & H$_2$ & no\\ HH~54~B$_3$& 0.58 & 0.067 $\pm$ 0.013 & 0.0145 $\pm$ 0.0023 & 173 $\pm$ 8 & 185 $\pm$ 10 & H$_2$ & no \\ HH~54~C3 & 0.85 & 0.046 $\pm$ 0.020$^b$ & 0.054 $\pm$ 0.014 & 184 $\pm$ 21 & 165 $\pm$ 20 & H$\alpha$ & no\\ HH~54~E & 0.86 & 0.027 $\pm$ 0.008 & 0.0039 $\pm$ 0.0015$^b$ & 28 $\pm$ 19 & 16 $\pm$ 41 & H$_2$ & yes \\ HH~54~F1 & 0.09 & 0.072 $\pm$ 0.024 & 0.084 $\pm$ 0.019 & 312 $\pm$ 12 & 324 $\pm$ 13 & H$\alpha$ & no\\ HH~54~G & 1.00$^a$ & 0.134 $\pm$ 0.057$^b$ & 0.013 $\pm$ 0.006$^b$ & 67 $\pm$ 21 & 61 $\pm$ 33 & [\ion{S}{ii}] & yes \\ & 0.08 & 0.155 $\pm$ 0.015 & 0.0146 $\pm$ 0.0017 & 85 $\pm$ 7 & 89 $\pm$ 9 & H$\alpha$ \\ HH~54~G0 & 1.00$^a$ & 0.2 $\pm$ 0.1$^b$ & 0.020 $\pm$ 0.007$^b$ & 28 $\pm$ 16 & 220 $\pm$ 20 & [\ion{S}{ii}] & yes \\ & 0.12 & 0.05 $\pm$ 0.02$^b$ & 0.012 $\pm$ 0.002 & 40 $\pm$ 20 & 230 $\pm$ 13 & H$\alpha$ \\ HH~54~G1 & 1.00$^a$ & 0.239 $\pm$ 0.067 & 0.02 $\pm$ 0.009$^b$ & 79 $\pm$ 15 & 76 $\pm$ 27 & [\ion{S}{ii}] & yes \\ & 0.06 & 0.214 $\pm$ 0.031 & 0.0177 $\pm$ 0.0039 & 85 $\pm$ 12 & 85 $\pm$ 19 & H$\alpha$ \\ HH~54~G2 & 1.00$^a$ & 0.12 $\pm$ 0.11$^b$ & 0.017 $\pm$ 0.0077$^b$ & 70 $\pm$ 35 & 316 $\pm$ 26 & [\ion{S}{ii}] & no \\ & 0.37 & 0.125 $\pm$ 0.019 & 0.0097 $\pm$ 0.0026 & 70 $\pm$ 13 & 143 $\pm$ 19 & H$\alpha$ \\ HH~54~G3 & 1.00$^a$ & 0.291 $\pm$ 0.059 & 0.0299 $\pm$ 0.0077 & 76 $\pm$ 11 & 80 $\pm$ 15 & [\ion{S}{ii}] & yes \\ & 0.10 & 0.134 $\pm$ 0.025 & 0.0068 $\pm$ 0.0025$^b$ & 66 $\pm$ 16 & 67 $\pm$ 38 & H$\alpha$ \\ HH~54~H1 & 0.49 & 0.033 $\pm$ 0.013$^b$ & 0.0063 $\pm$ 0.0017 & 55 $\pm$ 30 & 199 $\pm$ 17 & H$\alpha$ & yes \\ HH~54~H2 & 0.10 & 0.158 $\pm$ 0.017 & 0.0228 $\pm$ 0.0019 & 41 $\pm$ 5 & 256 $\pm$ 4 & H$\alpha$ & yes \\ HH~54~H3 & 1.00$^a$ & 0.062 $\pm$ 0.023$^b$ & 0.012 $\pm$ 0.004 & 127 $\pm$ 4 & 273 $\pm$ 16 & H$\alpha$ & no \\ & 0.50 & 0.079 $\pm$ 0.017 & 0.007 $\pm$ 0.003$^b$ & 66 $\pm$ 12 & 140 $\pm$ 35 & H$_2$ \\ HH~54~M & 1.00 & 0.071 $\pm$ 0.019 & 0.069 $\pm$ 0.021 & 70 $\pm$ 14 & 67 $\pm$ 19 & H$\alpha$ & yes\\ HH~54~Q1 & 1.00$^a$ & 0.165 $\pm$ 0.103$^b$ & 0.0171 $\pm$ 0.0078$^b$ & 12 $\pm$ 20 & 8 $\pm$ 28 & [\ion{S}{ii}] & yes\\ & 0.97 & 0.093 $\pm$ 0.023 & 0.0084 $\pm$ 0.0023 & 7 $\pm$ 22 & 349 $\pm$ 30 & H$\alpha$ \\ HH~54~Q3 & 0.99 & 0.097 $\pm$ 0.018 & 0.0069 $\pm$ 0.023 & 79 $\pm$ 12 & 79 $\pm$ 22 & H$\alpha$ & yes\\ HH~54~X1~A & 0.57 & 0.079 $\pm$ 0.015 & 0.055 $\pm$ 0.018 & 105 $\pm$ 9 & 107 $\pm$ 16 & H$\alpha$ & yes\\ HH~54~X1~C & 0.38 & 0.025 $\pm$ 0.012$^b$ & 0.0065 $\pm$ 0.0015 & 225 $\pm$ 30 & 186 $\pm$ 14 & H$\alpha$ & no \\ HH~54~Y2 & 1.00 & 0.082 $\pm$ 0.014 & 0.0057 $\pm$ 0.0013 & 25 $\pm$ 7 & 23 $\pm$ 12 & H$\alpha$ & yes \\ & 0.59 & 0.071 $\pm$ 0.026$^b$ & 0.0098 $\pm$ 0.0037$^b$ & 19 $\pm$ 16 & 40 $\pm$ 20 & H$_2$ \\ HH~54~Y3 & 0.06 & 0.145 $\pm$ 0.026 & 0.0097 $\pm$ 0.0026 & 37 $\pm$ 9 & 32 $\pm$ 18 & H$\alpha$ & yes\\ \hline \end{tabular}} \medskip Notes: $^{a}$ only 3 points in the fit; $^{b}$~below 3$\sigma$. \end{table}