A corona in meteorology is a phenomenon created by diffraction of the light from Sun or Moon by individual water droplets or sometimes tiny crystals of ice in a cloud. It consists of several pastel coloured rings around the Sun. A corona is different than the Halo in that it’s much smaller and is created by the diffraction of light, as opposed to refraction.

Visible in the image is the solar corona with the Sun masked out by the Halley sign post.