Solar activity continued at low levels during the past 24 hours with
four active regions on the visible disk. The largest events were a
C1.0 on May 20 from the northeast limb and a C1.0/Sf, also on May 20,
from Region 4439 that was accompanied by Type-III radio sweeps. This
region was responsible for the majority of the period’s activity,
which otherwise included a B8.7 flare on May 20 from Region 4...