The phenomenon occurred around 11.27 am on Monday.
PHOTO: Vikranth (IIA, Bengaluru)
Bengaluru: Astronomers at the Indian Institute of Astrophysics (IIA) on Monday captured a magnificent phenomenon called a sun halo, which occurred around 11.27 am.
Halos are caused by light refracting (bending of light when it passes between two mediums) through hexagonally shaped ice crystals present in the atmosphere.
Since light refraction depends on the colour or wavelength, it causes a colour gradient to be seen with red on the inside and blue on the outside. This also causes light to be smeared across the outside of the halo as the light is deviated there from just inside the ring structure.
The angular diameter or the angle the diameter subtends with respect to an observer is 22 degrees, hence the name '22⁰ sun halo'.
Light from the moon can also form a halo and is called a 'moon ring' or 'winter halo'.