The nature of far-infrared dust emission toward main sequence stars, whether
interstellar or circumstellar, can be deduced from submillimeter photometry. We
present JCMT/SCUBA flux measurements at 850 microns toward 8 stars with large
photospheric excesses at 60-100 microns. 5 sources were detected at 3-sigma or
greater significance and one was marginally detected at 2.5-sigma. The inferred
dust masses and temperatures range from 0.033 to 0.24 Earth masses and 43-65 K
respectively. The frequency behavior of the opacity, tau_nu ~ nu^beta, is
relatively shallow, beta < 1. These dust properties are characteristic of
circumstellar material, most likely the debris from planetesimal collisions.
The 2 non-detections have lower temperatures, 35-38 K and steeper opacity
indices, beta > 1.5, that are more typical of interstellar cirrus. The
confirmed disks all have inferred diameters > 2'', most lie near the upper
envelope of the debris disk mass distribution, and 4 are bright enough to be
feasible for high resolution imaging.Comment: accepted by Ap