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Sunspots and Solar Flares

Solar activity is accompanied by strong magnetic fields. The magnetic fields around sunspots are over a thousand times stronger than the sun's normal magnetic field, which is comparable in strength to the Earth's magnetic field. Sunspots are active regions where the strong magnetic fields have erupted through the upper layers of the sun sometimes giving rise to solar flares. To better understand how sunspot activity influences solar flares, astronomers trace the flow of gases through the various layers of the sun to better grasp the shapes and strengths of the magnetic fields along the way.


Visible Image of Sun

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(figure 2.2)

Layered just below the sun's atmosphere, the photosphere shines rather uniformly in the visible portion of the spectrum. A few sunspots show as dark regions in this picture, where the strong magnetic fields prevent the light from radiating off the photosphere. Some of these sunspots are as large as our own planet!

The Sun's Transition Layer

UV Image of Sun

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(figure 2.4)

This ultraviolet image shows a level of the transition layer, the innermost layer of the sun's atmosphere, that has a temperature of 180 thousand degrees Fahrenheit. Regions where strong magnetic fields concentrate great amounts of gas are white, indicating strong emissions. At the poles, magnetic fields extend straight out into space, carrying gases with them. Thus we see no electromagnetic emissions.

The Sun's X-rays

X-Ray Image of Sun

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(figure 2.15)

X-ray images of the sun reveal its hottest, outermost layer called the corona. The gases in the corona are affected by the magnetic fields much the same way as the transition layer gases. The dark regions are where the sun's magnetic field extends into outer space, carrying with it the hot gases. The bright regions show where the coronal gases are trapped in the snarls of the magnetic fields of active regions.

Sunspot Polarities

Sunspot Polarities

JPEG Image (32K); Credits and Copyrights

(figure 2.8)

This image is intended to reveal the polarity of the sunspots present when this image was produced. Just like magnets sunspots have both poles. The red coloring signifies north poles, while blue coloring signifies south poles. This polarity is important in understanding how the magnetic fields interact to produce the violent eruptions that result in solar flares.

Note: Take optical from Australian server, and other images from the The New Astronomy book.

Note: Looking for more BIMA images to incorporate.

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