Sunspot used in a sentence

Sunspot in a sentence as a noun

[1]That said, my professor would say that it's too early to infer much from this cycle's low sunspot number.

Research like this verifies common assumptions, but to me they always have a sunspot study feel to them.

Unfortunately, there were no sunspot observations for the 13th and 14th centuries to to show whether the start of the Little Ice Age occurred with a solar minimum.

Perhaps nobody's written a sunspot-finding computer vision algorithm that consistently produces the results they want, in a format vaguely compatible with the traditional drawings?