\begin{table}%T5
%%\centering
\par
\caption{Calculated geometric albedos for different mixtures of water 
 ice + astronomical silicates and different grain sizes.}
\label{astro_silicate_albedo}
$$
\begin{array}{p{2.7cm}p{2.7cm}p{2.7cm}}
\hline\hline
\noalign{\smallskip}
Mixture$^{{a}}$  &Grain size &Albedo$^{{b}}$\\
                        &[$\mu$m]    &\\
\noalign{\smallskip}
\hline
\noalign{\smallskip}
3\%	&100	&0.02\\
15\%	&10	&0.06\\
30\%	&10	&0.11\\
80\%	&1	&0.33\\
\noalign{\smallskip}
\hline
\end{array}  
$$
$^{{a}}$~Percentage of water ice in the mixture water ice + astronomical silicates. $^{{b}}$~Geometric albedo.
\end{table}