Sundog over Denholme, Yorkshire, last night.
It looks like a bit like a rainbow but no rain is involved. Instead, sunlight is refracted by ice crystals in the atmosphere. Just as refraction by water produces a spectrum in a rainbow, so refraction by tiny air-borne ice crystals creates the colours seen in a sundog. The meteorolgical term is parhelion.
Here are two earlier images of sundogs, also shot in Yorkshire.