The Bayesian Kepler periodogram is a mathematical algorithm, used to detect single or multiple extrasolar planets from successive radial velocity measurements of the star they are orbiting. It involves a Bayesian statistical analysis of the radial velocity data, using a prior probability distribution over the space determined by one or more sets of Keplerian orbital parameters. This analysis may be implemented using the Markov chain Monte Carlo (MCMC) method. The method has been applied to the HD 208487 system, resulting in an apparent detection of a second planet with a period of approximately 1000 days; however, this may be an artifact of stellar activity. The method was also applied to the HD 11964 system, where it found an apparent planet with a period of approximately 1 year; this was not found in re-reduced data, suggesting that this detection was an artifact of the Earth's orbital motion around the Sun.