Surge of solar activity
Wednesday, March 26th, 2008With little warning, three large sunspots have materialised in the last 24 hours, one of which unleashed the biggest solar flare so far this year.
Three new sunspot pairs have appeared and are growing rapidly. From left to right they are designated 989, 988 and 987, part of Solar Cycle 23. Image: NASA/SOHO
Although the young Solar Cycle 24 is underway, the magnetic polarity of the new sunspots associates them with the old Cycle 23. These sunspots harbor huge amounts of energy for strong solar flares, and yesterday, an M2 class eruption unleashed a coronal mass ejection into space, emitting radio bursts audible in shortwave receivers on Earth. An M-class flare rates as a medium-sized flare, and can cause brief radio blackouts on the Earth.
National Oceanic and Atmospheric Administration forecasters estimate a 50% chance of more M-flares during the next 24 hours, providing a good opportunity for amateur astronomers to monitor the Sun.
UV image of the Sun showing the three new sunspot regions. A solar wind stream flowing from the dark coronal hole above the furthermost right sunspot could reach the Earth on 28 or 29 March. Image: NASA/SOHO