  We simulate the formation of planetary systems around Alpha Centauri B. The
N-body accretionary evolution of a 1/r disk populated with 400-900 lunar-mass
protoplanets is followed for 200 Myr. All simulations lead to the formation of
multiple-planet systems with at least one planet in the 1-2 MEarth mass range
at 0.5-1.5 AU. We examine the detectability of our simulated planetary systems
by generating synthetic radial velocity observations including noise based on
the radial velocity residuals to the recently published three planet fit to the
nearby K0V star HD 69830. Using these synthetic observations, we find that we
can reliably detect a 1.8 MEarth planet in the habitable zone of Alpha Centauri
B after only three years of high cadence observations. We also find that the
planet is detectable even if the radial velocity precision is 3 m/s, as long as
the noise spectrum is white. Our results show that the greatest uncertainty in
our ability to detect rocky planets in the Alpha Centauri system is the unknown
magnitude of ultra-low frequency stellar noise.
