πF_n and P_s as functions of the planet’s rotation angle (in degrees), for a Jupiter-like model planet with a spot on its equator. Curves are shown for spots covering 0.3% (blue, dashed-dotted line), 1% (red, dashed line), 2% (green, dotted line), or 4% (black, solid line) of the planetary disk. The planetary phase angle α is 90° and λ = 0.55  μm. Calculations have been done at rotation angle steps of 20°.