April 20, 2011

Spinning Sunspots Create Giant Solar Flare

Researchers at the University of Central Lancashire studied the largest solar flare recorded in nearly five years. The solar eruption in February was caused by five rotating sunspots working in concert, BBC News reports.

Solar flares are eruptions on the surface of the sun which begin as concentrated magnetic fields and are visible as sunspots. As the magnetic fields build up, they twist and erupt, releasing vast amounts of heat, light and radiation."Twisting the Sun's magnetic field is like twisting an elastic band. At first you store energy in the elastic, but if you twist too much the elastic band snaps, releasing the stored energy.

Dr. Daniel Brown, of the University of Central Lancashire explains in a statement: "Rotating sunspots are an extremely efficient way to inject energy into the magnetic field of the Sun's atmosphere. With five sunspots rotating at the same time, enough energy has been injected into the atmospheric magnetic field to produce the largest solar flare seen for almost five years."

The flare occurred on February 15, when the Sun released the largest recorded solar flare since later 2006 and the first flare of the current solar cycle to be classified as the most powerful, "X-class".

That flare was associated with what is known as a coronal mass ejection (CME), which launches billions of tons of charged particles toward the Earth. Such CMEs are known to disrupt satellites and telecommunications, but despite its size, February's event had little effect because the alignment between the magnetic fields of the CME and the Earth served to dampen its effects.

Brown will present the findings at the RAS National Astronomy Meeting in Llandudno, Wales, on Wednesday 20th April 2011.


Image Caption: The Sun at 1.50am on 15th February 2011 using composite data of the Sun's surface from SDO/HMI and the Sun's million degree corona from SDO/AIA. The cutout region shows (bottom) the five rotating sunspots of the active region (AR 11158), and (top) the bright release of light from the X class flare. Image credit: Image produced by D. Brown (UCLan). Data courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.


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