Dependency test of measured v sin i on spot coverage. Shrinking polar caps from 30° radius by 5° steps with a constant equatorial belt between −30° and + 30° and −25° and + 25° latitudes are represented by diamonds and stars, respectively; the effect of a huge shrinking polar cap from 45° radius by 5° steps with a thin equatorial belt between −10° and + 10°, and without equatorial belt, are represented by plusses (vertical structures from the right to the left). The starting v sin i of 26.5 is represented by a dashed line, around it is seen the effect of an equatorial belt without a polar cap marked with stars; crosses, squares and triangles denote shrinking equatorial belts from −30° and + 30° with 5° steps and with constant radii of polar caps of 15°,20° and 25°, respectively (horizontal structures upwards). Below: two representative starting configurations are given to visualize the spots.