Big Sunspot Group Has Flare Potential
The sunspot group AR2778 is the largest of the new solar cycle. This photo was taken by NASA's Solar Dynamics Observatory (SDO) late Wednesday morning, Oct. 28. NASA / SDO The largest sunspot group of new Solar Cycle 25 is getting out attention this week. If you have a small telescope equipped with a safe solar filter, take a look. Although the individual sunspots are only modest-sized, the group as a whole extends across 62,000 miles (100,000 km). Its official name is Active Region (AR) 2778. The sun isn't a rigid body like the Earth but spins at rates that vary with latitude. NASA Because the sun turns on its axis from east to west about once every 27 days, the sunspot group moves further to the west each day. It's currently in the southwestern part of the disk, so we have a few more days of observation before it rotates around to the backside. Notice I used the word "about" when describing the sun's rotation period. Unlike the rigid Earth, our star is a