Heavenly rings are a type of atmospheric phenomenon that can be seen around the sun or moon. The two most common types of heavenly rings are HALOS and coronas. HALOS are circular arcs of light that appear to encircle the sun or moon, while coronas are more diffuse and appear as a halo of light around the sun or moon. Both HALOS and coronas are caused by the refraction of light through ice crystals in the atmosphere.