Courtesy of Spaceweather.com
New sunspot AR2781 is growing larger and turning toward Earth. This movie from NASA’s Solar Dynamics Observatory shows its development over the past 24 hours:
This sunspot will be facing Earth for the next ~10 days as solar rotation carries it across the face of the sun. Based on its size, AR2781 could become a source of strong solar flares. So far, though, it has been mostly quiet, unleashing only two minor C-class explosions.
AR2781 is the biggest sunspot of new Solar Cycle 25. Its trailing dark core alone is about the size of Neptune. This makes it an easy target for backyard solar telescopes. Amateur astronomer Philippe Tosi sends this picture from Nîmes, France:
To take the picture, Tosi used an H-alpha filter tuned to the red glow of solar hydrogen. It shows the hot magnetic maelstrom swirling through the sun’s atmosphere just above the sunspot group. Looking at this photo, it is easy to believe that a solar flare is in the offing. Stay tuned.