What's going on? Life's Little Mysteries, a sister site to Space.com, asked Jim Kaler, the University of Illinois astronomer who squelched the excitement over the aforementioned exploding Betelgeuse and who has written books on the day and night sky. The double sun image is an effect of optical refraction, Kaler said, but it's a "pretty darn rare" one, and one not fully explained by science.
Several related atmospheric optical effects are fully explained by science. Sun dogs, sunset mirages, sun pillars and sun halos are all relatively common and well understood. But not this effect.