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A parhelion (plural parhelia), or sun dog is a bright patch of light occurring on or near the 22° halo on the right and/or left of the Sun caused by the refraction of the sunlight by plate-like hexagonal ice crystals in the atmosphere. These patches of light are often curved (along with the halo) and can be quite bright at times giving them the nickname of mock sun. A parhelion is often colorful like a rainbow, but more subtle, with red on the inner side and blue on the outer side. The sun dogs will typically appear on the 22° halo when viewed near the horizon, but they will move further out as the sun gains altitude.
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