Since we are studying the Sun, I decided to choose this image of a "Sun halo" taken in Stockholm. Due to the snowy, frigid weather and dryness of the air, there are millions of ice crystals ( hexagonal and symmetrical in structure) in the atmosphere. These ice crystals are acting like lenses, which basically just means that they are bending rays of light (or refracting) creating two virtual images of the Sun on the left and right side of the actual Sun. The scientific phenomenon behind ice crystal halos is similar to what causes rainbows, which are produced when sunlight is reflected off of and refract water droplets. As sunlight enters through one end of the ice crystal's face and exits through an opposing face, it results in a refracting angle typically of 22 degrees (calculated by finding the angle of minimum deviation by using the index of refraction that equals 1.31 and the apex angle of a prism that equals 60 degrees). These halos (also called sun dogs) are best seen when the Sun appears to be low in the Earth's atmosphere, such as sunset, because these ice crystals tend to flutter down towards the ground
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