[SFDXA] Spaceweather News - The Sun sputters back to life

[Bill]

*SOLAR WIND, INCOMING: *A stream of solar wind is approaching Earth. 
Estimated time of arrival: *Jan. 18th*. Its source is a southern hole 
<https://spaceweather.com/images2021/15jan21/ch.jpg> in the sun's 
atmosphere. NOAA forecasters expect the solar wind speed to top 500 km/s 
when the stream arrives, probably sparking Arctic auroras. *Aurora 
alerts:* SMS Text <https://spaceweatheralerts.com>.

*THE SUN SPUTTERS BACK TO LIFE: *Solar Cycle 25 really is underway. 
Breaking a string of 12 spotless days, a new sunspot (AR2796) is 
emerging in the sun's southern hemisphere, inset in this magnetic map 
from NASA's Solar Dynamics Observatory (SDO):

<https://spaceweather.com/images2021/15jan21/mag_wholedisk.jpg>
*Above:* False colors in this SDO magnetogram indicate magnetic 
polarity: Green +, yellow -

The +/- polarity of this sunspot marks it as a member of new Solar Cycle 
25. Old Solar Cycle 24 sunspots would be the opposite, -/+, according to 
Hale's Law <http://adsabs.harvard.edu/full/1925ApJ....62..270H>.

AR2796 is small and so far poses no threat for strong flares. It may not 
be the only sunspot, however. NASA's STEREO-A spacecraft is monitoring 
an active region 
<https://spaceweather.com/images2021/16jan21/farside.png> just behind 
the sun's eastern limb. It could be a larger sunspot group soon to appear.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/sfdxa/attachments/20210116/01b6aebe/attachment.html>