Pulsating or final phase aurora. Ektachrome photo by John R.
Winckler, 23 October 1990, from University of Minnesota O'Brien
Observatory, Marine-on-the-St. Croix, Minnesota.
"Omega band," during breakup phase. Ektachrome
photo by John R. Winckler, 14 July 1991, from University of Minnesota
O'Brien Observatory, Marine-on-the-St. Croix, Minnesota.