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NAM 19: Rotating sunspots spin up a super solar flare

Last Updated on Wednesday, 20 April 2011 09:59
Published on Friday, 15 April 2011 17:44

 The largest solar flare recorded in nearly five years was triggered by interactions between five rotating sunspots. Researchers at the University of Central Lancashire studied observations of the flaring region of the Sun taken by NASA's Solar Dynamics Observatory over a period of five days. Dr Daniel Brown will present the findings at the RAS National Astronomy Meeting in Llandudno, Wales, on Wednesday 20th April 2011.


"Sunspots are features where magnetic field generated in the Sun’s interior pushes through the surface and into the atmosphere," said Dr Brown. "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. Similarly, rotating sunspots store energy in the Sun's atmospheric magnetic field. If they twist too much, the magnetic field breaks releasing energy in a flash of light and heat which makes up the solar flare."


The flare occurred at 1.44am on 15th February 2011, when the Sun released the largest recorded solar flare since December 2006 and the first flare of the current solar cycle to be classified as the most powerful “X-class”. Looking at five days of SDO observations that included this flare, Dr Brown found that the active region that flared contained five newly emerged sunspots. All five of the sunspots rotated between 50 and 130 degrees, some in a clockwise and some in an anticlockwise direction, over the five days of observations.

“Rotating sunspots are an extremely efficient way to inject energy into the magnetic field of the Sun's atmosphere,” said Dr Brown.  “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 5 years.”

In addition to the large X-class flare, the same region also released over 40 smaller flares during the five days studied.



brown_lowresImage 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.

SDO movie for NAM press release can be downloaded by using this link, it is in mpeg format and is about 32 MB in size.

This movie shows the dynamics of the Sun's atmosphere over 6 days as seen by NASA's Solar Dynamics Observatory (SDO). It uses composite data from two instruments, the surface data is from SDO/HMI, and the atmospheric data (at around 1,000,000 degrees) is from SDO/AIA. The right-hand inset shows a close up of active region 11158 from both of these instruments. The sunspots are seen to emerge and undergo a twisting motion in the solar surface. The response fo the coronal loops in the atmosphere shows rapid brightenings throughout the movie which are the solar flares being released.

Movie credit: Movie produce by D. Brown (UCLan). Data courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.



Dr Daniel Brown

University of Central Lancashire

Tel: 44 (0)1772 893305

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.



NAM 2011 Press Office (0900 – 1730 BST, 18-21 April only)

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Dr Robert Massey

Royal Astronomical Society

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Anita Heward

Royal Astronomical Society

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NAM 2011

Bringing together around 500 astronomers and space scientists, the RAS National Astronomy Meeting 2011 (NAM 2011: will take place from 17-21 April in Venue Cymru (, Llandudno, Wales. The conference is held in conjunction with the UK Solar Physics (UKSP: and Magnetosphere Ionosphere and Solar-Terrestrial Physics (MIST: meetings. NAM 2011 is principally sponsored by the RAS and the Science and Technology Facilities Council (STFC:


The Royal Astronomical Society

The Royal Astronomical Society (RAS:, founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3500 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.


The Science and Technology Facilities Council

The Science and Technology Facilities Council (STFC: ensures the UK retains its leading place on the world stage by delivering world-class science; accessing and hosting international facilities; developing innovative technologies; and increasing the socio-economic impact of its research through effective knowledge exchange. The Council has a broad science portfolio including Astronomy, Particle Astrophysics and Space Science. In the area of astronomy it funds the UK membership of international bodies such as the European Southern Observatory.


Venue Cymru

Venue Cymru ( is a purpose built conference centre and theatre with modern facilities for up to 2000 delegates. Located on the Llandudno promenade with stunning sea and mountain views; Venue Cymru comprises a stunning location, outstanding quality and exceptional value: the perfect conference package.