Published in Appl. Opt. 54, B93-B96 in 2015
H.E. Edens and G.P. Können
We present a stacked and
contrast-enhanced image comprised of 12 digital photographs that shows a series
of color hues in the correct order and location to be part of the seventh-order
rainbow. The observation was made on September 22, 2013, near Magdalena
in New Mexico (USA). The seventh-order rainbow is located at 64° from the Sun
in a region of the sky with little interference from the zero-order glow. The
color hues in the image range from red to blue-violet, spanning about 12° in
total extent; their locations generally agree with a numerical Debye-series
simulation of the seventh-order rainbow. Despite the low color contrast of the
seventh-order rainbow, the current observation indicates that it is feasible with
current digital-imaging technology to detect this higher-order rainbow in
near-ideal atmospheric conditions.