Friday, February 25, 2011

Amazing Sunspot Video

Over 100 years ago astronomer George Ellery Hale discovered that sunspots are magnetic disturbances on the surface of the Sun.  These magnetic disturbances slow down the flow of energy out from the Sun's interior, cooling a region of its surface (called the photosphere) enough to make it look like a dark spot.

Hale spent a lot time time studying the Sun and its spots. I am sure that he would have been overjoyed to see the video in my Sunspots on the Rise post a few days ago, but he would have been completely bowled over by this next one.

It shows the development of the same sunspot group (# 1158), but this time the view was not taken with visible light.  Instead it was taken with the Solar Dynamics Observatory's Helioseismic and Magnetic Imager, which delivers a picture of the magnetic disturbances on the Sun's photosphere.

White represents magnetic north and black magnetic south.  When watching the video it is very easy to see that the upper regions of the sun are dominated by convection.  You may recall that with convection hot fluids rise while cooler ones sink.  Convection is what powers Earth's weather & plate tectonics, allows hot air balloons float and so much more.

Being so close to us, it is almost easy to forget that the Sun is a star.  The stars seem changeless, but like the Sun they too are boiling, energetic dynamic places.

You can see more images from the Solar Dynamics Observatory, across many wavelengths of light here.

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