Terrestrial planet orbits in the habitable zones of exoplanetary system

We have investigated whether terrestrial planets can exist in orbits in known exoplanetary systems such that life could have emerged on those planets. We have shown that Rho CrB and 47 UMa could have terrestrial planets in orbits that remain confined to their habitable zones for biologically significant lengths of time. We have also shown that the Gliese 876 and Ups And systems are very unlikely to have such orbits.