Keck and APF radial velocities of HD7924

The new companions have masses of 7.9 and 6.4M_{Earth}_, and orbital periods of 15.3 and 24.5 days. We perform a joint analysis of high-precision radial velocity data from Keck/HIRES and the new Automated Planet Finder Telescope (APF) to robustly detect three total planets in the system.

We refine the ephemeris of the previously known planet using 5yr of new Keck data and high-cadence observations over the last 1.3yr with the APF. With this new ephemeris, we show that a previous transit search for the inner-most planet would have covered 70% of the predicted ingress or egress times. Photometric data collected over the last eight years using the Automated Photometric Telescope shows no evidence for transits of any of the planets, which would be detectable if the planets transit and their compositions are hydrogen-dominated.