  We present a spectroscopic survey of the newly-discovered Canes Venatici
dwarf galaxy using the Keck/DEIMOS spectrograph. Two stellar populations of
distinct kinematics are found to be present in this galaxy: an extended,
metal-poor component, of half-light radius 7'.8(+2.4/-2.1), which has a
velocity dispersion of 13.9(+3.2/-2.5) km/s, and a more concentrated
(half-light radius 3'.6(+1.1/-0.8) metal-rich component of extremely low
velocity dispersion. At 99% confidence, the upper limit to the central velocity
dispersion of the metal-rich population is 1.9 km/s. This is the lowest
velocity dispersion ever measured in a galaxy. We perform a Jeans analysis on
the two components, and find that the dynamics of the structures can only be
consistent if we adopt extreme (and unlikely) values for the scale length and
velocity dispersion of the metal-poor population. With a larger radial velocity
sample and improved measurements of the density profile of the two populations,
we anticipate that it will be possible to place strong constraints on the
central distribution of the dark matter in this galaxy.
