\begin{table}%t3
\caption{\label{TabEffective}Effective wavelength and bandwidth (in~square brackets) in each band (both in~$\mu$m), for a~K2~spectral type spectrum and a~\unit[4250]~{K} blackbody spectrum.}
%\centering
\par
\begin{tabular}{l c c}
\hline \hline \noalign{\smallskip}
    Filter name & K2 spectrum & \unit[4250]~{K} Planck  \\ 
  \hline
   Johnson-$U$ & 0.361 [0.059] & 0.359 [0.061] \\     
   Johnson-$B$ & 0.457 [0.079] & 0.451 [0.090] \\
   Johnson-$V$ & 0.557 [0.085] & 0.556 [0.086] \\
   Johnson-$R$ & 0.691 [0.205] & 0.693 [0.204] \\
   Johnson-$I$ & 0.870 [0.230] & 0.869 [0.229] \\
   2MASS-$J$ & 1.240 [0.160] & 1.239 [0.166] \\
   2MASS-$H$ & 1.640 [0.250] & 1.646 [0.248] \\
   2MASS-$K_{\rm s}$ & 2.150 [0.260] & 2.154 [0.254] \\[2pt]
 \hline
\end{tabular}
\end{table}