Largest Sunspot In Over 24 Years Accompanied By Numerous Solar Flares

Chuck Bednar for redOrbit.com – Your Universe Online
An area of intense and complex magnetic fields known as an active region rotated into view on October 18, growing into the largest phenomenon of its kind in more than two decades and producing 10 significant solar flares, NASA revealed on Friday.
Labeled AR 12192, the region was the largest active region in 24 years and was so big that it could be observed without a telescope for those looking at the sun with eclipse glasses during the partial solar eclipse on October 23. Active regions are measured in micro-hemispheres, with 1 MH equal to approximately 600,000 square miles, and AR 12192 reached 2,750 MH at its maximum, making it the 33rd largest active region ever recorded.
There have been 32,000 active regions that have been tracked and measured since 1874, the US space agency noted, and AR 12192 was the largest since AR 6368 reached 3,080 MH on Nov. 18, 1990. The five largest active regions ever observed were between 4,000 and over 6,000 MH, all of which took place between 1946 and 1951.
During its trip across the front of the sun, AR 12192 produced six X-class flares (the largest types of solar flares) and four strong M-class flares (which are one-tenth as strong as X-class flares), NASA explained. The number provides more information about its strength, in that an M2 is twice as intense as an M1, and an M3 is three times as intense.
The dates and peak times (in EDT) of the large solar flares from AR 12192 are as follows:
• Oct. 19, 1:01 am: X1.1
• Oct. 21, 9:59 pm: M8.7
• Oct. 22, 10:28 am: X1.6
• Oct. 24, 5:41 pm: X3.1
• Oct. 25, 1:08 pm: X1.0
• Oct. 26, 6:56 am: X2.0
• Oct. 26, 8:34 pm: M7.1
• Oct. 27, 6:09 am: M6.7
• Oct. 27, 10:47 am: X2.0
• Oct. 28, 11:32 pm: M6.6

“Despite all the flares, this region did not produce any significant coronal mass ejections” or CMEs, which are giant clouds of solar particles that could affect technology if they reach near-Earth space, explained Alex Young, a solar scientist at the Goddard Space Flight Center. “You certainly can have flares without CMEs and vice versa, but most big flares do have CMEs. So we’re learning that a big active region doesn’t always equal the biggest events.”
“Having so many similar flares from the same active region will be a nice case study for people who work on predicting solar flares,” added Dean Pesnell, project scientist for NASA’s Solar Dynamics Observatory at the Goddard facility in Greenbelt, Maryland. “This is important for one day improving the nation’s ability to forecast space weather and protect technology and astronauts in space.”
NASA scientists were able to capture images of the sunspot using the Solar Dynamics Observatory (SDO), while the Geostationary Operational Environmental Satellite (GOES) system measured X-ray output from the sun from October 19 through October 28, the agency said. AR 12192 rotated onto the far side of the sun on October 30, but NASA believes that it could continue to involve, and a new version of it could rotate back into view in 14 days.
—–
Follow redOrbit on Twitter, Facebook and Pinterest.