Still quite a bit of sunspot activity, but nothing dangerous.

Spörer was the first to note a prolonged period of low sunspot activity from 1645 to 1715.

These are unpredictable, influenced by a number of factors including sunspot activity, and can also be seen only on a clear night.

The first was an increase in sunspot activity earlier in the summer.

This is probably caused by sunspot activity, since they are invariably the wrong way round.

In 1848 he devised a way of quantifying sunspot activity.

An analysis of when and where the sunspot activity is shifting.

His graph follows almost exactly the cycle of sunspot activity.

Major quakes have taken place during periods of low sunspot activity.

Radio and television reception is disrupted during increased sunspot activity.