104 Spotless Days & Limb Darkening

The picture of the Sun today shows again a Sun without any sunspots. So far this year, 104 spotless days are registrated; in 2017, it took a full year for those 104 spotless days. This means we are heading towards a solar minimum.

The picture also shows the Sun is more bright at the center and darker towards the edges. This phenomena is called Limb Darkening - which I will explain later (when I have time :)