  We present observations of thermal emission from fifteen transneptunian
objects (TNOs) made using the Spitzer Space Telescope. Thirteen of the targets
are members of the Classical population: six dynamically hot Classicals, five
dynamically cold Classicals, and two dynamically cold inner Classical Kuiper
Belt Objects (KBOs). We fit our observations using thermal models to determine
the sizes and albedos of our targets finding that the cold Classical TNOs have
distinctly higher visual albedos than the hot Classicals and other TNO
dynamical classes. The cold Classicals are known to be distinct from other TNOs
in terms of their color distribution, size distribution, and binarity fraction.
The Classical objects in our sample all have red colors yet they show a
diversity of albedos which suggests that there is not a simple relationship
between albedo and color. As a consequence of high albedos, the mass estimate
of the cold Classical Kuiper Belt is reduced from approximately 0.01 Earth
masses to approximately 0.001 Earth masses. Our results also increase
significantly the sample of small Classical KBOs with known albedos and sizes
from 21 to 32 such objects.
