The secret structure of the sun: Nasa maps enormous, swirling plasma flows to reveal inner workings of the star

December 6, 2013 12:41 PM

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The secret structure of the sun: Nasa maps enormous, swirling plasma flows to reveal inner workings of the star

Scientists have long-predicted the sun contains giant cell structures, 15 times the diameter of Earth.

But despite their huge size, the massive structures have, up until now, eluded researchers.

In the convective zone, which is the outermost 30 per cent of the sun, rising plasma carries heat generated by nuclear fusion in the sun’s centre.

The denser plasma, which is also cooler, then sinks, driving further convection and creating circulating loops.

These are called convection cells and some are 15 times the diameter of Earth.

Now, David Hathaway, a Nasa researcher who 30 years ago worked on the problem as an intern, claims to have discovered the cells.

His finding supports a decades-old explanation as to why the sun rotates about 30 per cent faster near its equator than it does near its poles.

The denser plasma, which is also cooler, then sinks, driving further convection and creating circulating loops.

These are called convection cells and some are 15 times the diameter of Earth.

In 1801, astronomer William Herschel noticed smaller versions of these cells, about 1,000 km across, which became known as ‘granules’.

By the 1960s scientists had discovered ‘supergranules,’ which were around 30,000 km across.

However, researchers have since predicted the existence of even bigger ‘giant cells,’ roughly 200,000 km across.

It has taken so long to prove these giant cells exist because they move slowly relative to other solar features.

Material within the granules move at around 3,000 metres per second and supergranules flow at 500 metres per second.

Mr Hathaway and fellow researchers used Nasa’s Solar Dynamics Observatory to monitor the sun every 45 seconds over a couple of months.

They were able to determine that large groups of supergranules were being moved by an underlying presence - the long-sought giant cells.

The cells are important to understanding the sun's weather and could scientists better understand where sunspots form.

The research team now hopes to observe how magnetic fields respond to flows within the giant cells.

Finding the connection between flow and magnetism could allow scientists to better predict the behaviour of solar storms and how they'll affect the solar system.

Source: dailymail.co.uk

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