In 1611, with the aid of a telescope he built himself, he became one of several independent discoverers of sunspots (the others included Galileo, who unjustly accused Scheiner of claiming priority). He believed them to be small bodies in orbit round the Sun, and calculated their ‘orbital inclination’ to the ecliptic as 7° 30′; the present-day value for the Sun’s axial inclination is 7° 15′.