\begin{table}%t1
\caption{\label{tab:sources}Characteristics of the science and
  calibration targets.} 
%%\centerline

 {\small \begin{tabular}{*{8}{c}}
\hline\hline
\multicolumn{8}{c}{Science targets} \\ 
\hline
Source & Spec type & Age & RA & Dec & $F_\ast$ at 1~$\mu$m &
$F_{\rm disc}$ at 10~$\mu$m & Predicted disc size\\ 
HD & & Gyr & & & mJy & mJy & mas\\
\hline
69~830&K0V&2$^a$ & 08 18 23.95 & --21 37 55.8&872 & 102 & 80  \\
$\eta$ Corvi & F2V & 1.3$^b$ & 12 32 04.23 & --16 11 45.6 & 1736 & 371 & 90 \\
\hline
\multicolumn{8}{c}{Calibrators} \\
\hline
Source & \multicolumn{2}{c}{Spectral type} & RA & Dec &
\multicolumn{2}{c}{$F_\ast$ at 10~$\mu$m} & Angular size  \\ 
HD & \multicolumn{2}{c}{} & & & \multicolumn{2}{c}{mJy} & mas\\
\hline 
61935 & \multicolumn{2}{c}{G9III} & 07 41 14.83 &--09 33 04.10 &
\multicolumn{2}{c}{9490} & $2.24 \pm 0.01$ \\
73840 & \multicolumn{2}{c}{K3III} & 08 40 01.47 &--12 28 31.30 &
\multicolumn{2}{c}{12312} & $2.40 \pm 0.01$ \\
95272 & \multicolumn{2}{c}{K1III} & 10 59 46.46 &--18 17 55.56 &
\multicolumn{2}{c}{9510} & $2.24 \pm 0.01$  \\
116870 & \multicolumn{2}{c}{K5III} & 13 26 43.17 &--12 42 27.60 &
\multicolumn{2}{c}{10416} & $2.58 \pm 0.01$  \\ 
107218 & \multicolumn{2}{c}{M4III} & 12 19 42.59 & --19 11 55.97 &
\multicolumn{2}{c}{7913} & $2.16 \pm 0.02$ \\
\hline
\end{tabular}}
\medskip
For science targets the stellar flux was determined by Kurucz model
profiles scaled to the 2MASS~$K$ band photometry. Total fluxes taken   from IRS photometry of the targets were then used to determine the  disc flux, with the predicted size being based on SED fitting with a blackbody. For calibration targets the angular size is as given by the CalVin tool available at   \url{http://www.eso.org/instruments/midi/tools}. \protect\\ Key: $^a$~age from \citet{beichman06}; $^b$ age from \citet{mallik}: note that the \mbox{X-ray} luminosity of this star is close to the mean value for the Hyades cluster which may suggest a younger age of 600--800~Myr   \citep{stern95}.   
\end{table}