The orbits of terrestrial planets in the habitable zones of known extrasolar planetary systems

We show that terrestrial planets could survive in variously restricted regions of the habitable zones of 47 Ursae Majoris, epsilon Eridani, and rho Coronae Borealis, but nowhere in the habitable zones of Gliese 876 and nu Andromedae. The first three systems between them are representative of a large proportion of the 90 or so extrasolar planetary systems discovered by mid-2002, and thus there are many known systems worth searching for terrestrial planets in habitable zones. We reach our conclusions by launching putative Earth-mass planets in various orbits and following their fate with a mixed-variable symplectic integrator.