I have been sketching sunspots now for two months, as part of the research project. The last few days there has been a really large sunspot that I have watched as it traverses the face of the sun. This spot is larger than the Earth! Even in my little 1 inch aperture 18th Century replica telescope, I could see that the spot was large and it also was surrounded by a large "penumbra" - the gray area surrounding the black sunspot. So I got out a much larger telescope, set it up, and photographed the sun and the sunspot. Notice that it is not a round spot, and there is white area that is slowly cutting into the spot. It will be interesting to see how this progresses over the next few days. Be sure and click on the image to see more detail.
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Well, this was not the usual Sunspots 101 lesson by Ken Spencer that I expected. I've always heard the term "sunspots" but still don't know anything about them. Do they pose a danger to earth? Are they pieces of the sun that can detach and become meteors? I know these questions are elementary and maybe even stupid, and you're doing research, but why? Is there a theory behind how sunspots affect our atmosphere? By the way, before I read your caption, I thought this was a food stain on one of your white shirts and thought, OH, NO! he's going to show us everything that needs to be pre-treated before washing!
My apologies for not being more thorough in discussing sunspots. First, they post no risk to us on earth. The Sun (and other stars as well) is a complex mechanism. There are three inner zones or layers, and the Sun's atmosphere consists of three layers. The inner layer of the sun’s atmosphere is called the photosphere. Photo means “light,” so the photosphere is the sphere that gives off visible light. It is in this layer that sunspots are seen. This is complex, but basically, there are magnetic lines of force on the Sun, as there are on Earth. These lines of magnetic flux on the Sun become twisted, and erupt through the photosphere. These lines then inhibit convection and result in reduced surface temperature compared to the surrounding photosphere. Thus the reduced temperature results in the spots being darker than their surroundings. What we do worry about on the Sun are solar flares, the flare ejects clouds of electrons, ions, and atoms through the corona of the sun into space. These clouds typically reach Earth a day or two after the event. They disrupt Earth's ionosphere and interfere with radio communications. There is another form of energy release from the Sun, called a coronal mass ejection. It is a massive burst of gas and a magnetic field arising from the solar corona and being released into the solar wind. When that energy arrives on Earth, it can be picked up by power lines and the electrical surge from that can blow out transformers and damage the electrical grid. That's the thing we most worry about. It is not hazardous to humans, just to our infrastructure.
Thank you! This stuff is fascinating and I wish I had become more interested in it when I was younger, but somehow, things more earthbound seemed the only stuff that mattered. Now, I fear I'd never remember the tiny details that seem to be important in making this universe (and others) function. But thanks, Prof. Ken for the lesson!
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