  The evolved solar-type stars 16 Cyg A & B have long been studied as solar
analogs, yielding a glimpse into the future of our own Sun. The orbital period
of the binary system is too long to provide meaningful dynamical constraints on
the stellar properties, but asteroseismology can help because the stars are
among the brightest in the Kepler field. We present an analysis of three months
of nearly uninterrupted photometry of 16 Cyg A & B from the Kepler space
telescope. We extract a total of 46 and 41 oscillation frequencies for the two
components respectively, including a clear detection of octupole (l=3) modes in
both stars. We derive the properties of each star independently using the
Asteroseismic Modeling Portal, fitting the individual oscillation frequencies
and other observational constraints simultaneously. We evaluate the systematic
uncertainties from an ensemble of results generated by a variety of stellar
evolution codes and fitting methods. The optimal models derived by fitting each
component individually yield a common age (t=6.8+/-0.4 Gyr) and initial
composition (Z_i=0.024+/-0.002, Y_i=0.25+/-0.01) within the uncertainties, as
expected for the components of a binary system, bolstering our confidence in
the reliability of asteroseismic techniques. The longer data sets that will
ultimately become available will allow future studies of differential rotation,
convection zone depths, and long-term changes due to stellar activity cycles.
