  We present a program designed to obtain age-rotation measurements of
solar-type dwarfs to be used in the calibration of gyrochronology relations at
ages of several Gyr. This is a region of parameter space crucial for the
large-scale study of the Milky Way, and where the only constraint available
today is that provided by the Sun. Our program takes advantage of a set of wide
binaries selected so that one component is an evolved star and the other is a
main-sequence star of FGK type. In this way, we obtain the age of the system
from the evolved star, while the rotational properties of the main sequence
component provides the information relevant for gyrochronology regarding the
spin-down of solar-type stars. By mining currently available catalogs of wide
binaries, we assemble a sample of 37 pairs well positioned for our purposes: 19
with turnoff or subgiant primaries, and 18 with white dwarf components. Using
high-resolution optical spectroscopy, we measure precise stellar parameters for
a subset of 15 of the pairs with turnoff/subgiant components, and use these to
derive isochronal ages for the corresponding systems. Ages for 16 of the 18
pairs with white dwarf components are taken from the literature. The ages of
this initial sample of 31 wide binaries range from 1 to 9 Gyr, with precisions
better than 20% for almost half of these systems. When combined with
measurements of the rotation period of their main sequence components, these
wide binary systems would potentially provide a similar number of points useful
for the calibration of gyrochronology relations at very old ages.
