Question

What are the cooler spots on the sun called?

Answer 1

The sunspot has a central dark area which is called the Umbra, which appears dark because it's cooler than the rest of the sun's surface, with some lighter spots, and that center is surrounded by a lighter filamentary area, called the Penumbra, that flows outward. Hope this helps!:)<span />

Answer 2

I think a sunspot. Its been awhile so I may be wrong, but I'm pretty sure it is sunspot.