Our closest star, the Sun, has been without sunspots for some time now, but after a false start earlier this year it has sunspots again. In the latest image taken today by the SOHO (SOlar and Heliospheric Observatory) satellite, a group of several sunspots can be clearly seen.

Sunspots appear again on the Sun

Over the last few years the Sun has been in the low ebb of its 11 year magnetic cycle, which means the absence of sunspots was entirely normal. The actual cycle is 22 years long with a flip of the magnetic poles at the lowest point every 11 years. The cycle time does vary, but this time it has been over a year since the excpected return to sunspot activity. The Sun is a complex cauldron of stormy gasseous fusion that we are still learning about, so variation in expected behaviour adds a lot to our knowledge of its workings.

Sunspots are caused by a very simple phenemenon called magnetic turbulence. As the magnetic strength of the Sun increases, so does turbulence in its magnetic flow lines. Just like the flow lines seen using a regular magnet and iron filings, the Sun radiates giant magnetic loops from pole to pole. When turbulence increases to a point where it can disrupt the flows, a tortured and wrenched flow line breaks from its regular positon and crashes into the surface, ripping holes in the hot outer layer and creating cooler patches. It is these cool patches that we see as sunspots.

You can keep an eye on the daily activities of the Sun at the SOHO website: http://sohowww.nascom.nasa.gov/home.html

Happy Sunspotting, Spacers!

Image credit: STEREO, SOHO, NASA/ESA
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