PENANG: Is it a bird? Is it a plane? No, it is a solar halo.
Between 1.30pm and 2.15pm yesterday, many in George Town witnessed an unusual phenomenon in the midday sky – a rainbow around the sun.
Universiti Sains Malaysia's astronomy enthusiast Assoc Prof Dr Chong Hon Yew said the halo was an atmospheric optical phenomenon caused by a refraction of sunlight through ice crystals in the sky.
“Solar halos can occur a few times a year, usually on hot and clear days. However, most of the time we miss them as we seldom look at the sky during the day,” he said.
Chong, who lectures in the School of Physics, said that in science classes, students learnt that a rainbow was created when a prism refracted the sunlight into seven colours.
Similarly, the crystals acte as mini prisms in the case of solar halos where its always coloured red on the inside and blue on the outside, he said.
“Sometimes, two patches of light with tails can be spotted at opposite ends of the outer halos. They are called sundogs. The last time, I saw them here was two years ago.
A businessman, Terrence Ng, 52, said it was the first time he witnessed such a phenomenon and he believed it was a good sign.
“A halo is usually associated with holiness while the sun is a source of light and energy. Hopefully, it will bring good luck to everyone.”
(Original headline: 45-minute solar halo enthralls Penangites )
