\begin{table}%T4
%\catcode`\#=\active \def#{\hphantom{0}}
\caption{Titan's limb-darkening parameter.}
\label{T:kTitan}
%\centerline
{
\begin{tabular}{cccll}
  \hline\hline
  \noalign{\smallskip}
  Minnaert  & Range & Solar phase   & \hfil Method\hfil& \hfil Reference\hfil \\
  parameter $k$     &       & angle $\alpha$&        	    &                      \\
  \hline
  \noalign{\smallskip}
  1 & ${\ge} 1^{c,d}$	& $6^\circ25$ 		& Lunar occultation 
	& Elliot et~al. (\cite{elliot75})   	\\
  %
  0.95 & $0.8{-}1.15^c~$	& $5^\circ6$		& Speckle interferometry 
	& Nisenson et~al. (\cite{nisenson81}) 	\\
  %
  0.9  & $0.68{-}1.0^{a,e}$ 	& $6^\circ25$ 		& Cloud model
	& Smith (\cite{smith80})	\\
  %
  0.87$^b$  & $0.773{-}0.942^a~$	& $29^\circ6$		& Voyager 1
	& Sromovsky et~al. (\cite{sromovsky81})	\\
  %
  0.79$^b$  & $0.77{-}0.85^a~$	& $28^\circ1$		& Pioneer
	& Tomasko \& Smith (\cite{tomasko82})	\\
  %
  0.90  & $0.83{-}1.15^c~$	& $\sim$$5^\circ5$	& Modulated photometry 
	& Present work ($R=2847~$km) \\
 \hline
\end{tabular}}
\par
\smallskip
$^a$ The range corresponds to different filters. \\
$^b$ Calculated mean value for the Hipparcos broad-band photometric system $H_p$.\\
$^c$ The range is given as probable values from the given technique.\\
$^d$ Value of $k$ yielding residuals within one standard deviation of the minimum.\\
$^e$ The range also corresponds to different parts of the entire disc.
\end{table}