A scientist in the U.K. photographed a sequence of dazzling arcs and halos of light encircling the sun, including a remarkable ring of light that circled the sky.
Alan Fitzsimmons, an astronomer at Queen’s University Belfast in Northern Ireland, recorded the amazing light show over Belfast’s Botanic Gardens on May 28. Fitzsimmons told Live Science the show lasted 30 minutes.
Spaceweather.com reported seeing strange lighting beams in various regions of Northern Ireland, northern England, and Scotland.
Fitzsimmons said millions of small, precisely positioned ice crystals in the high sky, which commonly accompany thin cirrus clouds, generate the arcs and halos.
“If the winds are very uniform up there, the hexagonal-shaped crystals align,” he said. “This allows sunlight refracting through them to combine, just as light refracts through a prism, producing arcs and circles of sunlight.”
The sun’s ethereal “halo” and light arcs recorded in images of ultra-rare phenomenon
Fitzsimmons’ image shows a 22-degree halo, a pair of “sundogs,” and a complete parhelic circle, the line that bisects the circle and forms a full circle around the sky.
According to Spaceweather.com, a full parhelic circle requires at least five internal reflections from millions of ice crystals catching sunbeams concurrently.
The “eyelids” above and below the 22-degree halo may be a confined halo and a supralateral arc.
Fitzsimmons noted the image’s rarest and most “impressive feature” is the parhelic circle. He said he had only watched it twice. The other occurrences are more prevalent than most think.
“The sun can be quite bright when they [the phenomena] are visible, so to notice them, you need to block out the sun with your thumb or a tree,” Fitzsimmons said. “But anytime it’s sunny with high-altitude wispy clouds, it’s worth taking a look to see if there’s a halo or maybe something more.”
A Finnish photographer captured a rainbow-colored pollen corona around the sun on May 30. Unless some of the sun’s light is obstructed, these rings, generated by pollen grains dispersing light, are hard to see.
Tiny atmospheric ice crystals can also create strange visual phenomena like polar stratospheric clouds, which shine like rainbows in the Arctic, and night-shining clouds (also called noctilucent clouds), which will become more visible in the Northern Hemisphere in June and July.