\begin{table}%t4
\caption{\label{exponentAfrho}Exponent $a$, together with its rms error, $\sigma_a$, of
the relation~Af$\rho(r_{\rm h})\sim r_{\rm h}^{-a}$ for components~C and~B.} 
\small%\centerline
 {
\begin{tabular}{c c c c c c}
\hline \hline 
73P-C(Jan21-Apr16) & $\rho$ (km)& $a\pm\sigma_a$&
73P-B & $\rho$ (km)& $a\pm\sigma_a$\\
\hline
No correction & 10~000 & 3.40 $\pm$ 0.25 & No correction & 10~000 & 2.31 $\pm$ 0.36\\
              & 5000  & 3.03 $\pm$ 0.23 &               &  5000 & 2.12  $\pm$  0.31\\
              & 4000  & 2.98 $\pm$ 0.25 &               &  4000 & 2.02 $\pm$ 0.26\\
Silicates     & 10~000 & 3.46 $\pm$ 0.24 & Silicates     & 10~000 & 2.39 $\pm$ 0.30\\
              & 5000  & 3.09 $\pm$ 0.22 &               &  5000 & 2.21 $\pm$ 0.25\\
              & 4000  & 3.04 $\pm$ 0.24 &               &  4000 & 2.10 $\pm$ 0.22\\
Mixed         & 10~000 & 3.36 $\pm$ 0.26 & Mixed         & 10~000 & 1.76 $\pm$ 0.34\\
              & 5000  & 3.00 $\pm$ 0.24 &               &  5000 & 1.57 $\pm$ 0.34\\
              & 4000  & 2.94 $\pm$ 0.25 &               &  4000 & 1.47 $\pm$ 0.33\\
Organics      & 10~000 & 3.37 $\pm$ 0.25 & Organics      & 10~000 & 1.97 $\pm$ 0.34\\
              & 5000  & 3.01 $\pm$ 0.23 &               &  5000 & 1.79 $\pm$ 0.32\\
              & 4000  & 2.95 $\pm$ 0.25 &               &  4000 & 1.68 $\pm$ 0.29\\
\hline
\end{tabular}}
\medskip
Values of $a$ with no Af$\rho$ phase angle correction and with the correction for pure silicates, mixed silicates and organics, and pure organics composition, in the three photometric apertures used
in the text, are shown.
\end{table}