Kenneth G. Smith shot this photo of anticrepuscular rays in the eastern sky over Texas at sunset. He wrote:
They kept changing like an aurora borealis until the sun fully set.
Anticrepuscular rays have the same source as crepuscular rays, sometimes called sunrays. We’ve all seen sunrays converging on the sun, columns of sunlight streaming up from the horizon or down through gaps in clouds. If your sky is extremely clear and pure, you might also see those rays converging towards the point on the sky opposite the sun. Here’s more about anticrepuscular rays.