Ratio of maximum polarization of exoplanetary system during transit calculated with SphM to that calculated with PPM stellar atmospheres depending on gravity a) and temperature b) for all considered host stars at 4500 Å. The color scale in a) describes the temperature of the host stars and in b) presents their surface gravity. The size of the circles indicates the planet-to-star radius ratio. The dashed line indicates the equal value for maximum transit polarization obtained with SphM and PPM stellar atmospheres.