Parhelia - "Sun Dogs." From Wikipedia: "Sundogs are formed by plate-shaped hexagonal ice crystals in high and cold cirrus clouds or, during very cold weather, by ice crystals called diamond dust drifting in the air at low levels. These crystals act as prisms, bending the light rays passing through them by 22°. If the crystals are randomly oriented, a complete ring around the sun is seen --- a halo. But often, as the crystals sink through the air they become vertically aligned, so sunlight is refracted horizontally -- in this case, sundogs are seen."

I have seen them much brighter than this, but this was the first time I've ever had a camera handy when they appeared.