Sat Mar 23, 2024 11:33 pm by globalturbo
Breaking a string of 28 spotless days, a new sunspot (AR2750) is emerging in the sun’s southern hemisphere–and it’s a member of the next solar cycle. A picture of the sunspot is inset in this magnetic map of the sun’s surface from NASA’s Solar Dynamics Observatory. How do we know AR2750 belongs to the next solar cycle? Its magnetic polarity tells us so. Southern sunspots from old Solar Cycle 24 have a -/+ polarity. This sunspot is the opposite: +/-. According to Hale’s Law, sunspots switch polarities from one solar cycle to the next. AR2750 is therefore a member of Solar Cycle 25. Shortlived sunspots belonging to Solar Cycle 25 have already been reported on Dec. 20, 2016; April 8, 2018; Nov. 17, 2018; May 28, 2019; July 1, 2019; and July 8, 2019. The one on July 8, 2019, was significant because it lasted long enough to receive a number: AR2744. Record-keepers will likely mark it as the first official sunspot of Solar Cycle 25. If so, AR2750 would be the second.
https://youtu.be/tFaba1rjCLI
