"A sundog or sundog (scientific name parhelion, pluralparhelia, e.g. "with the sun") is a relatively common halo, an atmospheric optical phenomenon mostly associated with the refraction of sunlight by small ice crystals making up cirrus or cirrostratus clouds. Another term used is sunbow (an arch resembling a rainbow made by the sun shining through vapor or mist). Sundogs typically, but not exclusively, appear when the sun is low, e.g. at sunrise and sunset, and the atmosphere is filled with ice crystals forming cirrus clouds, but diamond dust and ice fog can also produce them. When sunlight passes through the sides of a flat crystal, both the angle of the sun rays and the orientation of the crystals affects the shape and colour of the sundogs. Misaligned or wobbling crystals produces colorful and elongated sundogs, while light passing through the crystal in non-optimal deviation angles (up to 50°) produces the "tail" of the sundog stretching away from the sun."