Mike Wall, SPACE.com Senior Writer

Date: 07 September 2011 Time: 12:30 PM E

This image taken by NASA’s Solar Dynamics Observatory watching the sun shows a powerful solar flare (center right) just minutes after it erupted on 6:20 p.m. EDT (2220 GMT) on Sept. 6, 2011. CREDIT: NASA/SDO/GSFC

This story was updated at 8:48 p.m. EDT.

Just as many Americans got back to work after the long Labor Day weekend, the sun jolted to life as well, unleashing a massive solar flare just one day after another sun storm sent a stream of particles racing toward Earth.

The X-class solar flare — the most powerful type of sun storm— erupted at 6:12 p.m. EDT (2212 GMT) on Tuesday (Sept. 6) and hit its peak strength eight minutes later, according to a space weather update by the National Oceanic and Atmospheric Administration (NOAA). The flare occurred less than 24 hours after another less intense but still dramatic solar storm.

The Tuesday event registered as an X2.1-class solar flare, while Monday’s storm topped out at a still-powerful M5, NOAA officials said. Strong solar flares are classified according to a three-tiered system: X-class flares are the most powerful, M-class are of medium strength and C-class are the weakest.

September solar storms

Researchers are still taking the measure of the big Tuesday sun storm. It may also have produced a coronal mass ejection (CME) aimed at Earth, researchers said, but as of Tuesday evening it was too early to tell.

CMEs are massive clouds of solar plasma that can streak through space at up to 3 million mph (5 million kph). CMEs that hit Earth can wreak havoc on our planet, causing disruptions in GPS signals, radio communications and power grids.

to read more, go to:    http://www.livescience.com/15933-sun-unleashes-massive-solar-flares.html