GROWING SUNSPOT: What a difference a day makes. On April 16th, sunspot AR1460 did not exist. Twenty-four hours later it was twice as big as the planet Earth. This April 17th movie from NASA’s Solar Dynamics Observatory shows sunspot genesis in action:
The sunspot’s magnetic field is still too simple for strong flares, but if the expansion continues apace, instabilities could develop that lead to explosions. Readers with solar telescopes should keep an eye on AR1460.
from: spaceweather.com