Rainbow and Supernumerary Bows at Sunset
June 26, 2010
The photo above, showing a lively rainbow and its accompanying supernumerary bows beneath the violet color of the primary bow, was taken from Amesbury, Massachusetts near sunset on June 12, 2010. Supernumerary bows result from diffraction of sunlight rather than from reflection and refraction, which are responsible for the formation of primary and secondary rainbows. The drops creating supernumeraries are considerably smaller than the raindrops that cause rainbows, perhaps only 0.5 mm in diameter. Note that the colors of the supernumeraries are more subdued and metallic than the vibrant rainbow colors.