Crystal type:
- Pyramidal crystals
- random
- Refraction at side face and pyramidal face
Occurrence:
- rare (about once a year)
Description
The 24° ring is a faintly colored ring of light with a reddish inner edge and a radius of 24° around the sun. It usually appears together with other halos that are produced by pyramidal crystals. Since it is very close to the 22° ring and the 23° ring, it is often only recognizable by the unusual width of the 22° ring or by a double color sequence, at least in the red part. It is also called Dutheil's halo. Pyramidal crystals with a vertical main axis also produce the 24° lateral arcs.
Origin
The 24° ring is formed by randomly oriented pyramidal crystals. The light passes through a prism face and a pyramidal face, which enclose an angle of 63.8°. The graphic above shows the light path.
Photos
Pyramidal halo phenomenon with rare rings, taken on 03/26/2013 in Dresden (Photo: Alexander Haußmann)
Pyramidal Halo Phenomenon in Finland on 05.06.2008 (Photo: Jari Luomanen)
Pyramidal halo phenomenon with caption (Photo: Jari Luomanen)