Overview of the sample systems and a comparison with the inner solar system architecture. Known giant planets of the sample are shown as brown circles, a thin brown line from periastron to apoastron showing their orbit’s span. Each system’s habitable zone, computed using the model detailed in Kopparapu et al. (2013), is shown as a thick green band, while the thin blue line indicates each system’s region of dynamical stability for additional inner planets as computed through Hill’s criterion detailed in Sect. 4.