This “ring around the sun” is a halo, an optical phenomenon that occurs from light interacting with ice crystals in the atmosphere. It’s not an uncommon phenomenon, but for those who have never seen one, you can imagine from the admiring upward gazes of Stephan and Armando in the next photo that it’s quite something to behold. Halos can appear around the moon as well as the sun.
These photos were taken while some remaining IceCubers were outside saying farewell to a group of folks who were leaving the Pole—in fact you can see their waiting plane in the photo above of the sun halo. Below, Stephan and Erik pose side by side after Erik’s return from an R&R trip to McMurdo, where he got to see the fruits of their retro-cargo-packing-labors from last month.