  We have used the Submillimeter Array (SMA) to make 1.3 millimeter
observations of the debris disk surrounding HD 15115, an F-type star with a
putative membership in the beta Pictoris moving group. This nearly edge-on
debris disk shows an extreme asymmetry in optical scattered light, with an
extent almost two times larger to the west of the star than to the east
(originally dubbed the "Blue Needle"). The SMA observations reveal resolved
emission that we model as a circumstellar belt of thermal dust emission. This
belt extends to a radius of ~110 AU, coincident with the break in the scattered
light profile convincingly seen on the western side of the disk. This outer
edge location is consistent with the presence of an underlying population of
dust-producing planetesimals undergoing a collisional cascade, as hypothesized
in "birth ring" theory. In addition, the millimeter emission shows a ~3 sigma
feature aligned with the asymmetric western extension of the scattered light
disk. If this millimeter extension is real, then mechanisms for asymmetry that
affect only small grains, such as interactions with interstellar gas, are
disfavored. This tentative feature might be explained by secular perturbations
to grain orbits introduced by neutral gas drag, as previously invoked to
explain asymmetric morphologies of other, similar debris disks.
