A sun dog or sundog (scientific name parhelion) is a relatively common atmospheric optical phenomenon associated with the refraction of sunlight by small ice crystals that make up cirrus or cirrostratus clouds. Sundogs typically appear as a bright and colorful patch in the sky at a position 22 degrees or more to the left and/or right of the sun. They are a halo. Other common associated phenomena, collectively called "ice halos," are the circumzenithal arc, upper tangent arc, parhelic circle, and lower tangent arc. There are many other named ice halo phenomena that can be seen given optimal conditions.