These are harmless “coronas!” The word “corona” is from mid-16th-century Latin meaning "garland, wreath, or crown."
It is also used to describe the rarefied gaseous envelope of our sun. A sun’s corona is only visible during a total solar eclipse as it surrounds the black disk of the moon. In the world of auroral displays, coronae are an aspect of formation describing the aurora as it passes overhead at the viewer's zenith. Though the walls of aurora stand straight-up into space, the ground-view illusion is that they converge to a center point above you. This perspective is similar to looking down a set of railroad tracks … though the rails are continuously parallel, they come together in the receding distance … the “vanishing point” or “Ponzo Illusion.”
Depending on the spread and power of the auroral display, these formations can cover just the center of night, half the sky, or even the entire sky like an “umbrella” shape. Auroral Coronae are one of the most powerful and vibrant types of aurora, and such displays have been measured pulsating across the stars with speeds in excess of 200 Km/sec.
There is, however, one affliction that can slightly hurt you while enjoying auroral corona viewing and it is a very real condition. This ailment is characterized by the clinical term “Aurora Neck”… and after a while, will force the afflicted individual to want to lie down flat in the snow!
All images © Dave Parkhurst www.TheAlaskaCollection.com