Last weekend the small ephermal sunspot materialized in the Sun’s northern hemisphere, then, hours later, vanished again. The magnetic field of the spot was reversed, marking it a member of the next solar cycle (see data e.g. HERE). Sunspot AR2727 appeared just north of the Sun’s equator. This one still belongs to the decaying Solar Cycle #24 that peaked back in 2012-2014. But its magnetic
polarity is already that of the other, still unnumbered sunspot high above it. They
are opposite.
According to Hale’s Law, this means the two sunspots belong to different solar cycles. The high latitude sunspot appears to be a harbinger of Solar Cycle #25. Solar cycles always mix together at their boundaries. Indeed,
ephemeral sunspots possibly belonging to Solar Cycle #25 have already
been reported
on December 20, 2016, and April 8, 2018. Now November 17, 2018, can be added to
the list. The slow transition between Solar Cycle #24 and Solar Cycle #25
appears to be underway.
