Javascript Menu by Deluxe-Menu.com


2019 News Releases

 

Year

 


A Sunspot from the Next Solar Cycle

Date : 08 / 07 / 2019
Author : DR Tony Phillips

How do we know this sunspot belongs to Solar Cycle 25? 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. AR2744 is therefore a member of Solar Cycle 25.

Solar cycles always mix together at their boundaries. Right now we are experiencing the tail end of decaying Solar Cycle 24. AR2744 shows that we are simultaneously experiencing the first stirrings of Solar Cycle 25. The transition between Solar Cycle 24 and Solar Cycle 25 is underway.

Shortlived “ephemeral sunspots” belonging to Solar Cycle 25 have already been reported on Dec. 20, 2016; April 8, 2018; Nov. 17, 2018; May 28, 2019 and July 1, 2019. Today’s sunspot is more important than those earlier examples because it has lasted long enough to receive a numerical designation: AR2744. Record-keepers will likely mark this as the first official sunspot of Solar Cycle 25.

This development does not mean Solar Minimum is finished. On the contrary, low solar activity will probably continue for at least another year as Solar Cycle 24 decays and Solar Cycle 25 slowly sputters to life. AR2744 is an important sign, however, that the next solar cycle is approaching.

Dr Tony Phillips
Space Weather Archive Link



Page Last Updated: Sunday 14 July 2019 at 11:58 hours by Peter Clee

 

Click Here To Return To Previous Page
© 2024 Wireless Institute of Australia all rights reserved.
The National Association for Amateur Radio in Australia
A member society of the International Amateur Radio Union (IARU)