Photos

Never seen anything like it! A full circle rainbow around the sun. Nearly blinded myself trying to photograph it, though!

Taken at Wat Sisaket, Vientiane, Laos - I was dashing about the temple complex trying to find a suitable foreground to complement this phenomenon before it dissipated (I think it lasted about 20 minutes or half an hour).

I've done some research, and this optical phenomenon seems to be what's called a 22° halo. It forms as sunlight is refracted in hexagonal ice crystals suspended in the atmosphere. As the light beam passes through two sides of the prism forming a 60° angle, the angle of minimum deviation is almost 22°. 22° halos form when the sky contains millions of poorly oriented ice crystals.

Like other ice halos, 22° halos appear when the sky is covered by thin cirrus clouds containing the ice crystals which causes the phenomenon.

More information on wikipedia.

Edited from original post to enhance colours and clone out the distracting foliage from the bottom corner.