46° halo

At solar elevations of 15–27°, 46° halos are often confused with the less rare and more colourful supralateral and infralateral arcs, which cross the parhelic circle at about 46° to the left and right of the sun.

The 46° halo forms when sunlight enters randomly oriented hexagonal ice crystals through a prism face and exits through a hexagonal base.

In addition, as many rays are deflected at larger angles than the angle of minimum deviation, the outer edge of the halo is more diffuse.

[3] To tell the difference between a 46° halo and the infralateral or supralateral arcs, one should carefully observe sun elevation and the fluctuating shapes and orientations of the arcs.

The supralateral arc always touches the circumzenithal arc, while the 46° halo only achieves this when the sun is located 15–27° over the horizon, leaving a gap between the two at other elevations.