Predicting Planets in Known Extrasolar Planetary Systems. III. Forming Terrestrial Planets

Recent results have shown that many of the known extrasolar planetary systemscontain regions which are stable for both Earth-mass and Saturn-mass planets.Here we simulate the formation of terrestrial planets in four planetary systems-- 55 Cancri, HD 38529, HD 37124, and HD 74156 -- under the assumption thatthese systems of giant planets are complete and that their orbits arewell-determined. Assuming the giant planets formed and migrated quickly, thenterrestrial planets may form from a second generation of planetesimals. In eachcase, Moon- to Mars-sized planetary embryos are placed in between the giantplanets and evolved for 100 Myr. We find that planets form relatively easily in55 Cnc, with masses up to 0.6 Earth masses and in some cases substantial watercontents and orbits in the habitable zone. HD 38529 is likely to support anasteroid belt but no terrestrial planets of significant mass. No terrestrialplanets form in HD 37124 and HD 74156, although in some cases 1-2 lone embryossurvive for 100 Myr. If migration occurred later, depleting the planetesimaldisk, then massive terrestrial planets are unlikely to form in any of thesesystems.Comment: New coauthor Kaib -- ApJ, in pres