3664-3697-3723

(No, those are not lottery numbers or the code to a bank vault. )

A great sunspot group came into view on May 1, 2024 and produced multiple solar flares, including the one that caused the aurora borealis to be seen as far south as Puerto Rico and Hawaii on May 10 and 11. It was labeled Active Region (AR) 3664 as seen in the top photo.

Not only was it large and powerful, it was also long lived. It remained visible clear across the solar disk as the sun’s rotation carried it to the western limb and then out of view. Two weeks later it returned, still large and flaring. Per protocol it was given a new number, 3697, when it reappeared, even though it is the same active region. The middle photo shows it once again about to be carried from view by the sun’s rotation.

It recently reappeared once more, and is now AR 3723 as seen on the bottom photo. It is still complex, has produced some minor flares but is not as large, and is diminishing in size. Still it is worth watching.

In over 20 years of solar observation, I have only seen two other sunspot groups remain visible during three complete solar rotations, but they were small, stable spots that didn’t produce any flares or magnetic storms that make northern lights. This latest group of sunspots, however, has created quite a show that has lasted nearly two months; a rare treat for sun watchers.

#sunspots #activeregion #solarflare #aurora #sun