Kolkata witnesses rare red-blue ring around Sun
A red and blue ring around the Sun, known as ‘22° halo’, was sighted in Kolkata on Saturday from 12:10-12:40 pm. The rare phenomenon occurs when the Sun’s or Moon’s rays get deflected/ refracted through the hexagonal ice crystals present in cirrus clouds, a researcher with the Birla Planetarium said. It was last observed in the city in April 2013.