Baily's beads

The Bailyschen pearls (English Baily 's beads), also called Perlschnurphänomen, are an optical phenomenon that can be observed during a total or annular eclipse. It was first described by the English astronomer Francis Baily in 1836.

The phenomenon is caused by the roughness of the lunar surface. Shortly before and after totality, the sun shines through the valleys between the mountains of the moon through it. Points of light on the edge of the moon, which are strung like pearls on a string appear for a few seconds. As a special case arises from a single point of light the diamond ring, such as in the illustration.