Sunspots

 I set my telescope up to project an image of the Sun onto a piece of paper. There are about half a dozen sunspots visible at the moment. This activity on the surface of the Sun will result in more charged particles streaming towards Earth and interacting with our magnetic field around the poles. Hence the Aurora Borealis is more likely to be seen.

 

 

Whilst I was at it, I noticed the dimming of the picture if I covered over part of the lens. Casting around for something to use in the photograph, I used my finger. That is my pointing finger, in case you were wondering! Notice that you don't get a shadow of the finger in the image. You still get the full image. The reason is that light from each part of the object is refracted by each part of the lens. In other words, there are many different routes light can take from the Sun to the paper. My finger blocked off a few of these routes so less light was able to get through and the image is dimmer overall.