Sunspot of new solar cycle - start of Solar Cylce 25

PTS

The new solar cycle has started!
AR12620, a complex group that started to appear at helio latitude 23S on Dec. 21.  This is the highest latitude of any Active Region in 2 years.
From HDI magnetograms, it is very clear that polarity reversal has taken place.
Attached are images observed on Dec 22, 2016 and magnetograms from SolarMonitor.org and SDO for reference.




Telescope: AP Starfire EDT 155 mm f/9.
stopped to 50 mm for disc images, with 4X telecentric lens (f/36) for closeups
filter: Solar Spectrum SO1.5/0.3A with CERF prefilter
Camera: Imperx 4M15
North is up, and east to the left.

PTS

Yes, the new solar cycle has started but much earlier, on 2015 June 8.
However, this group was not observed until 2015 June 16.
Attached are images observed on 2015 June 16 and 17, and magnetograms from SolarMonitor.org and SDO for reference.




Telescope: AP Starfire EDT 155 mm f/9.
stopped to 50 mm for disc images, with 4X telecentric lens (f/36) for closeups
filter: Solar Spectrum SO1.5/0.3A with CERF prefilter
Camera: Imperx 4M15
North is up, and east to the left.

PTS

I have to correct myself again, after recieving this email from Jan Jannsen of the Solar-Terrestrial Centre of Excellence (STCE) :

Dear Taksun Poon,

Thank you for your interest!

1. The reported AR12620 at S23-degree was also recorded and noted as sunspot of cycle 25.
This is indeed the sunspot that was indicated as a sunspot group of new solar cycle 25 in our news item at http://www.stce.be/node/359

2. Upon checking magnetograms on SolarMonitor.org, I found AR12365 on latitude S13, on 2015 June 08 also showed magnetic reversal.
That's correct. This group however is not considered as a SC25 group in view of its relatively low latitude. In a solar cycle, about 2-5% of all sunspot groups have such a reversed polarity.
More on these so-called anti-Hale regions, including a few additional examples, is at http://sidc.oma.be/news/286/welcome.html

Hope this helps. Please let us know if you have any further questions.

Kind regards,

Jan Janssens
STCE - http://www.stce.be/