Hi Catherine,

I think the name sunspot just came from the fact that from a distance they look like little blemishes, or spots on the solar disk. Early astronomers did not have the high-resolution data that we have now, so they could not see all of the detail of the spots. With high-resolution data, we can see that they are not perfectly round and they have a region of deep black (called the umbra) surrounded by a region of less black, or grey (called the penumbra). Early astronomers might have called them something else had they been able to see all of the detail.

Holly