Deep imaging of the Kuiper Belt with the Keck 10 meter telescope

We present a new, pencil-beam survey of the Kuiper Belt taken with the Keck 10 m telescope. The cumulative surface density of Kuiper Belt Objects meas ured to apparent red magnitude m(R) = 26.1 is 31(-14)(+12) deg(-2), while t o m(R) = 26.6 it is 40 +/- 33 deg(-2). These numbers are compatible with an extrapolation of the luminosity function deduced earlier from measurements in the 20 less than or equal to m(R) less than or equal to 25 range, and t hey confirm a Kuiper Belt differential size distribution index q similar to 4.