BENGALURU: “Hey! Have you noticed the halo around the sun?!” This was the most common message Bengalureans shared with each other around noon, a welcome distraction for Monday morning lockdown blues. While some saw a dark circle around the sun, others saw a rainbow encircling the star, and mobiles flashed copiously, capturing the phenomenon for eternity. In some places, a clear sky made the halo a delight to shoot, while in others, wispy clouds added a new dimension.
Experts and citizens were amazed at the variety of photographs coming in from different locations. Jawaharlal Nehru Planetarium director Pramod Galgali told TNIE that the 22 Degree Halo, or simply the Sun’s Halo, is not a rare sight, and that they were just observing it. Explaining its formation, he said, “Putting it simply, when thin clouds form around a bright object like the Sun or Moon, a halo-like structure is seen. It is dimmer around the Moon.”
On why it is called a 22 Degree Halo, he said it is because the halo is formed at a 22 degree angle from the horizon (where the horizon is a zerodegree angle and zenith a 90-degree angle). He said there are water crystals in the atmosphere, which are nothing but thin clouds, so when light passes through them, it is reflected in different colours, creating the halo effect. Officials at the planetarium said the formation of such halos is usual during the monsoon or pre-monsoon period, when the sun is bright, sky is clear and there are ice crystals in the atmosphere. “Visibility is different in different locations,” the officials explained.