View of 55 Cnc along the line of sight. With the star rotation, the light emitted by the half of the stellar disk moving toward the observer is blueshifted, while the light from the other half that moves away is redshifted. During the transit, the small super-Earth 55 Cnc e (shown as a black disk, to scale) mainly transits the blueshifted half of the stellar disk because of its high sky-projected obliquity λ = 72.4°.