On Sunday, May 12, 2013, at around 10 p.m. EDT, the sun released a solar flare classified as an X1.7, the first X-class flare of 2013. For those unfamiliar with how these events are classified, “X-class” represents the intensity of the flares, while the number provides information about its strength. The higher the number, the strong the flare.
This is worth noting because shortly after the X1.7 fired off, an X2.8-class flare occurred on Monday, May 13, at 12:05 p.m. EDT.
At the time it occurred, it was the third-largest flare of the current solar cycle, and the 16th X-class flare of the cycle to date. These credits were short lived, however, because after the lunch-time event, at 9:11 p.m. EDT on May 13, 2013, the sun emitted a third X-class flare, classified as an X3.2, the strongest of 2013 to date.
All flares were associated with coronal mass ejections (CMEs), none of which (thankfully) were directed at the Earth. The video below compiles imagery of the X1.7-class and X2.8-class flares, as well as their CMEs. Images were captured by NASA’s Solar Dynamics Observatory and from NASA and the European Space Agency’s Solar and Heliospheric Observatory.
The third CME — the one associated with the X3.2-class flare — left the sun at approximately 1,400 miles per second, which is considered particularly fast for a CME. Predictive modeling software indicates that it will soon catch up with the previous two CMEs released earlier in the day. The merged cloud of solar material is on path to pass by the Spitzer spacecraft, and may knock into the STERO-B and Expoxi spacecrafts.
All mission operators have been notified of the forthcoming avalanche of solar matter, and will likely put the spacecrafts into safe mode to protect the instruments.
The high number of solar flares occurring right now is common and was actually expected because the sun’s normal 11-year activity cycle is ramping up toward solar maximum, which is expected to occur at some point during 2013.
The first X-class flare of this 11-year cycle occurred on February 15, 2011, and there have been 17 X-class flares to date, the largest of which took place on August 9, 2011, and was classified as an X6.9.
Story via: nasa.gov
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