  A Bayesian multi-planet Kepler periodogram has been developed for the
analysis of precision radial velocity data (Gregory 2005b and 2007). The
periodogram employs a parallel tempering Markov chain Monte Carlo algorithm.
The HD 11964 data (Butler et al. 2006) has been re-analyzed using 1, 2, 3 and 4
planet models. Assuming that all the models are equally probable a priori, the
three planet model is found to be >= 600 times more probable than the next most
probable model which is a two planet model. The most probable model exhibits
three periods of 38.02+0.06-0.05, 360+-4 and 1924+44-43 d, and eccentricities
of 0.22+0.11-0.22, 0.63+0.34-0.17 and 0.05+0.03-0.05, respectively. Assuming
the three signals (each one consistent with a Keplerian orbit) are caused by
planets, the corresponding limits on planetary mass (M sin i) and semi-major
axis are 0.090+0.15-0.14 M_J, 0.253+-0.009 au, 0.21+0.06-0.07 M_J, 1.13+-0.04
au, 0.77+-0.08 M_J, 3.46+-0.13 au, respectively. The small difference (1.3
sigma) between the 360 day period and one year suggests that it might be worth
investigating the barycentric correction for the HD 11964 data.
