  We have analyzed a homogeneous set of observations of eighty-one
transneptunian objects obtained with the NIC2 camera on the Hubble Space
Telescope with the goal of identifying partially resolved binaries. Using
PSF-fitting we have identified six likely binaries in addition to the three new
binaries already found in this data set. We find that 11% of transneptunian
objects are binaries at separation and brightness limits of the NIC2 camera.
The identification of these new binaries significantly increases the known
lower limit to the binary fraction among transneptunian objects. The origin of
such a high fraction of binaries remains to be determined. Most interestingly,
detectable binaries appear to be about four times more common among the cold
classical disk than in the dynamically excited populations.
