How Beautiful the Parhelia

Parhelia, better known as sundogs, are bright spots (usually colorful) seen in the sky due to refraction in hexagonal ice crystals. They occur at an elevation equal to the sun and usually have an equal counterpart on the opposite side of the sun. To better understand the process for which they occur it is important to look at two components: Ice Crystal Orientation and Refraction Angles.

Photo from: http://www.arbeitskreis-meteore.de/ee01ee02/ee02_b.htm

Ice Crystal Orientation

Refraction Angles

Parhelia Photos (links)

Bibliography