\begin{table}%t1
\caption{Sample of protostars surveyed in Taurus. The infrared photometry and the spectral indices
are taken from Kenyon \& Hartmann (\cite{kenyon95}), except for
IRAS~04191+1523, whose {\it JHK}~photometry is from the 2MASS~database and classification from Motte \& Andr\'e (\cite{motte01}). The bolometric luminosities are from Motte \& Andr\'e (\cite{motte01}). IRAS did not resolve the systems IRAS~04108+2803~AB and
IRAS~04181+2654~AB and we assigned the same spectral index,
based on unresolved photometry, to both components and split
evenly the bolometric luminosity of the later system. The
classification of each source is based on the infrared
spectral indices (see text); "I'' stands for Class~I sources
and~"FS'' for flat spectrum sources. The last three columns
indicate whether the source~i) has at least one visual
companion within~10\arcsec, ii) is surrounded by an extended
nebulosity in our images (see also Park \& Kenyon \cite{park02}), and
iii) has an extended ($>$$1000$~AU) envelope as seen in
millimeter continuum mapping (from Motte \& Andr\'e \cite{motte01}).}\label{tab:sample1}
%\centering
\par
\begin{tabular}{lcccccccccc}
\hline  \hline
Object & $J$ & $H$ & $K$ & $\alpha^{2-12}_{{\rm IR}}$ &
$\alpha^{2-25}_{{\rm IR}}$ & Class & $L_{\rm bol} (L_\odot)$ & Comp? &
Opt neb? & Mm env? \\
\hline
IRAS~04016+2610 & 13.62 & 11.67 & 9.33 & 1.06 & 1.02 & I &
3.7 & N & Y & N \\
IRAS~04108+2803~B & 16.25 & 13.25 & 11.12 & 0.50 & 0.62 & FS
& 0.6 & N & N & N \\
IRAS~04113+2758 & 11.29 & 9.15 & 7.79 & --0.01 & 0.12 & FS &
$>$$1.6$ & Y & N & Y \\
IRAS~04158+2805 & 13.15 & 11.92 & 10.80 & 1.47 & 0.72 & I &
$>$$0.4$ & N & Y & N \\
IRAS~04169+2702 & 16.87 & 13.83 & 11.22 & 0.89 & 1.10 & I &
0.8 & N & Y & Y \\
IRAS~04181+2655 & 15.46 & 12.74 & 10.54 & 0.60 & 0.55 & I &
0.4 & N & N & N \\
IRAS~04181+2654~A & 15.90 & 12.74 & 10.58 & --0.00 & 0.10 &
FS & 0.25 & N & N & Y \\
IRAS~04181+2654~B & 18.11 & 13.64 & 10.81 & --0.00 & 0.10 &
FS & 0.25 & N & N & Y \\
IRAS~04191+1523 & 16.74 & 14.43 & 12.26 & & 
& I & 0.5 & Y & Y & Y \\
IRAS~04239+2436 & 15.61 & 12.96 & 10.58 & 1.27 & 1.15 & I &
1.3 & N & N & Y \\
IRAS~04248+2612 & 12.76 & 11.39 & 10.65 & --0.09 & 0.48 & FS &
0.4 & Y & Y & Y \\
IRAS~04260+2642 & 14.64 & 12.96 & 11.63 & 0.16 & 0.25 & FS &
0.1 & N & N & N \\
IRAS~04263+2426 & 10.84 & 9.06 & 7.80 & 1.02 & 0.74 & I & 7.0
& Y & Y & Y \\
IRAS~04264+2433 & 13.63 & 12.07 & 11.09 & 0.67 & 0.98 & I &
0.5 & N & N & N \\
IRAS~04295+2251 & 13.62 & 11.11 & 9.55 & 0.11 & 0.21 & FS &
0.6 & N & N & N \\
IRAS~04302+2247 & 14.20 & 12.35 & 11.07 &  & 0.15 &
FS & 0.3 & N & Y & N \\
IRAS~04325+2402 &  & 13.02 & 11.03 &  & 0.79
& I & 0.9 & Y & Y & Y \\
IRAS~04361+2547 & 16.07 & 12.88 & 10.55 & 1.27 & 1.55 & I &
3.7 & N & Y & Y \\
IRAS~04365+2535 & 17.28 & 13.39 & 10.62 & 1.08 & 1.27 & I &
2.4 & N & Y & Y \\
IRAS~04381+2540 & 16.21 & 14.32 & 12.00 & 1.20 & 1.31 & I &
0.7 & N & Y & Y \\
IRAS~04385+2550 & 12.61 & 10.72 & 9.65 & 0.14 & 0.18 & FS &
$>$$0.4$ & N & N & N \\
IRAS~04489+3042 & 13.74 & 11.58 & 10.11 & 0.18 & 0.31 & FS &
0.3 & N & N & N \\
\hline
\end{tabular}
\end{table}