Chi Cygni expands and dims, and then contracts and brightens over 408 days
This movie combines infrared images of the surface of Chi Cygni, obtained with IOTA, with visual brightness measurements provided by the American Association of Variable Star Observers (AAVSO). Chi Cygni demonstrates a 408-day-period of expanding and dimming, followed by contracting and brightening. Credit: Sylvestre Lacour, Observatoire de Paris.
