Circum Borealis

From the photographer: “Circumpolar star trails from the radar of the Grand Ballon (1394m), on a night where I noticed aurora borealis from France. You can see a really weak violet halo light of aurora in the background sky.”

Technical details: Stacked sequence of 240 photos, each 20s, Canon 6D, 14mm XP Samyang F2.4