A Sundog, technically, known as parhelion is an atmospheric optical phenomenon that consists of a concentrated patch of sunlight occasionally seen about 22° to the left or right of the Sun. It is caused by the refraction of sunlight off hexagonal plate-like ice crystals in the cirrus clouds. Sundogs typically appear when the sun is low, e.g. at sunrise and sunset. So, the pair of sundogs flanking the sun are aligned with the horizon. They tend to have red inner edges while the colours appear bluish-white at the outer edges. There are many mentions of sundogs in literature, art and scientific papers.
Sundog
