"Characterizing Exoplanetary Systems: The Search for Solar System Analogs"
For 10 years the California & Carnegie Planet Search has been collecting precision radial velocities of hundreds of Sun-like stars with ever-improving precision. Today, this temporal baseline allows us to detect exoplanets at orbital distances of ~ 5 AU including many in systems already known to harbor an inner exoplanet. Analysis of incomplete orbits of longer-period exoplanets allows us to peek beyond this 5 AU curtain, and recent hardware and software upgrades bring our RV precision to 1 m/s, allowing us to detect exoplanets of only a few earth masses. Together, these achievements have helped bring the number of known multiple-planet systems up to 20 (and counting) and test theories of planet formation and migration. Although it appears that multiplicity among exoplanets is common, the search for a true Solar System analog continues.