The top picture is a “timestack” of 5 photos, hence the star trails. You can also see an (albeit admittedly closer) airplane trail across the middle of that stack.
The second photo is a zoom crop of the object and incident in question, from the top photo stack. It was only visible for four 30-second exposures before completely disappearing.
The arch of light occurred during the first of the four ‘visible’ photos, shown in the third (bottom) picture. So, it did not occur during the direction change.
You ever see a prairie so pretty your heart breaks? Black Earth Rettenmund Prairie is 17 acres of prairie on a hillside in south-central Wisconsin that was never plowed, and it always takes my breath away.
Kihaku-Gato's Garden Blog (tumblr import) 