http://www.spaceweather.com/index.cgi
vom 20. August 2005:
....something soon ...SUNSPOT 798: What a difference a day makes. On August 19th, sunspot 798 was barely visible. Today, August 20th, it is five times wider than the entire planet Earth. Daily images captured by the Solar and Heliospheric Observatory (SOHO) show how quickly this 'spot has grown:
When sunspots develop at breakneck speed, their magnetic fields can become unstable and explode. Sunspot 798 now poses a threat for M-class solar flares.
grüße
frieder