In the case of a double halo, there is an additional outer ring with a radius of approximately 46 degrees from the sun's center. This outer ring forms due to the unique shape and alignment of ...

Though sun halos can happen year-round, they are especially noticeable in the winter when ice-filled cirrus clouds are more common.

Hong Kong on Tuesday witnessed a rare natural phenomenon, a halo around the sun, that can be experienced ... A large halo has an angular radius of 46 degrees and is dimmer than the smaller version.