Bangalore residents recently witnessed a bright rainbow ring around the sun for a few moments, a rare optical and atmospheric phenomenon known as a “22-degree circular Halo.”This phenomenon is commonly referred to as the 22-degree circular halo of the sun, or sometimes called the moon (also called moon ring or winter halo), occurs when the sun’s or moon’s rays are deflected/refracted through hexagonal ice crystals found in cirrus clouds

This is also known as the Kaleidoscopic Effect.

These halos are known as 22-degree halos because the halo or ring has an apparent radius of 22 degrees around the sun/moon.
Cirrus clouds, which are thin, detached, hair-like clouds, produce circular halos in particular. These clouds form at a height of more than 20,000 feet in the .
A halo, like a rainbow, is visible when viewed from the right angle, sometimes appearing only white but often with colours from the spectrum clearly visible.