It's no longer just the largest sunspot in more than 20 years; it's the sunspot that just won't quit. The solar region, known as Active Region 12192 (or AR 2192), has been ripping off solar flares for more than a week now, and has shown no signs of slowing down.
The region — which began forming as far back as 2008, and is still rich in electromagnetic activity — launched an X1 flare on Saturday (an X-class flare is the largest variety) and followed it up with an X2 flare each of the of the last two days. Friday featured an X-class solar flare too.
Sunday's was "the third X-class flare in 48 hours, erupting from the largest active region seen on the sun in 24 years," NASA spokesperson Karen Fox wrote in a recent online update. "An X2 is twice as intense as an X1, an X3 is three times as intense, etc."
Occasionally, major solar flares are accompanied by massive bursts of scorching plasma called coronal mass ejections, or CMEs. When these ejections leap from the sun and out into space they can generate extensive swirling electromagnetic storms that result in the colorful auroras seen as the waves of energy strike the Earth's poles.
So far, AR 2192 hasn't produced any CMEs.