The 9° ring is a white ring of light with a radius of 9° around the sun. It often occurs along with other halos produced by pyramidal crystals. However, it is rare for there to be enough pyramidal crystals to produce halos. Since the ring is quite close to the sun, it is difficult to see. Furthermore, it can easily be mistaken for
corona phenomena. The 9° ring is the
first inner ring of the rings produced by pyramidal crystals.
