  Discovery of transneptunian object (TNO) satellites and determination of
their orbits has recently enabled estimation of the size and albedo of several
small TNOs, extending the size range of objects having known size and albedo
down into the sub-100 km range. In this paper we compute albedo and size
estimates or limits for 20 TNOs, using a consistent method for all binary
objects and a consistent method for all objects having reported thermal fluxes.
As is true for larger TNOs, the small objects show a remarkable diversity of
albedos. Although the sample is limited, there do not yet appear to be any
trends relating albedo to other observable properties or to dynamical class,
with the possible exception of inclination. The observed albedo diversity of
TNOs has important implications for computing the size-frequency distribution,
the mass, and other global properties of the Kuiper belt derived from
observations of objects' apparent magnitudes and may also point the way toward
an improved compositional taxonomy based on albedo in addition to color.

Astrophysics