Saw this outside my house at midday today and grabbed the camera. It’s a 22° solar halo, caused by refraction of sunlight through ice crystal cloud (cirrostratus). It was one of the brightest I’ve ever seen and I could make out the colours of the rainbow (somewhat visible in the photo at the top but not quite as visible as in the real thing). The rainbow colours are reversed in that, in a true rainbow, red would be on the outside of the arc, blue on the inside, etc. 