This illustration shows how planet KELT-9 b sees its host star. Over the course of a single orbit, the planet twice experiences cycles of heating and cooling caused by the star's unusual pattern of surface temperatures. Between the star's hot poles and cool equator, temperatures vary by about 1,500 F (800 C). This produces a "summer" when the planet faces a pole and a "winter" when it faces the cooler midsection. So every 36 hours, KELT-9 b experiences two summers and two winters.