  We report the detection of dust emission at sub-millimeter wavelengths from
HD 107146, a G2V star with an age estimated to lie between 80 and 200 Myr. The
emission is resolved at 450um with a size 300 AU x 210 AU. A fit to the
spectral energy distribution gives a dust temperature of 51 K and dust mass of
0.10 Earth masses. No excess emission above the photosphere was detected at
18um showing that there is very little warm dust and implying the presence of a
large inner hole, at least 31 AU (~ 1'') in radius, around the star. The
properties of this star-disk system are compared with similar observations of
other systems. We also discuss prospects for future observations that may be
able to determine whether the inner hole is maintained by the dynamical effect
of an unseen orbiting companion.
