Wilson effect

The Wilson effect was discovered in 1769 by the Scottish astronomer and mathematician Alexander Wilson and affects the appearance of sunspots . Wilson found that the appearance of the umbra and penumbra of the sunspots - the darker central region of each sunspot and the semi-dark edge region visible in larger spots - changes just as if they were dents as the spots migrate from one edge of the sun to the other the light-emitting sun layer, the photosphere . According to the latest knowledge, this is actually the case: Sunspots are regions in which changes in the magnetic field make it possible to look down into layers several thousand kilometers deeper than the usual solar surface.