A fast growing sunspot caught the attention of astronomers over the weekend. Barely visible when the weekend began, sunspot AR1619 has blossomed into a large active region more than three times as wide as Earth. The Animation below is a 24-hour animation provided by NASA. AR1619 is the sunspot on the right side of the animation.
24 hour movie recorded by NASA's Solar and Heliospheric Observatory
So far the growing sunspot has not produced any significant flares, but the quiet is unlikely to continue if its expansion continues apace. Fast-changing magnetic fields on the sun have a tendency to reconnect and erupt. NOAA forecasters estimate a 20% chance of M-class solar flares during the next 24 hours.