A sunset generated this rainbow at 15:45 in the afternoon, november 01, 2011, over Mount Herzogstand, Germany.
Very sunny day, no clouds, no rain.
At the beginning the “rainbow” was very luminous and white and looked like a second sun, we were wondering what this is (two suns like on the planets of star wars? an ufo? Lol), some minutes later the colors appeared smoothly and we realized it is a rainbow.
After looking at the pictures on my PC I think this phenomenon is called a “halo”.
Nikon D90 AF-S 18-200 VR-II at 105mm, PSE9.