Stratosphere around at midlatitudes, and at about at the poles. Temperatures range from an average of near the tropopause to an average of near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere, reaching near in the Southern polar vortex. The mechanism describing the formation of the ozone layer was described by British mathematician Sydney Chapman in 1930. Molecular oxygen absorbs high energy sunlight in the UV-C region, at wavelengths shorter than about 240 nm. Radicals produced
S Sagittae leading to maximum, F4 at maximum, and G3 just before minimum brightness. S Sagittae is a yellow-white supergiant that varies between spectral types F6Ib and G5Ib. It is around six or seven times as massive and five thousand times as luminous as the Sun and is located around 2,000 light-years away from Earth. Its radius is 58.5 times that of the Sun. The radius, temperature, luminosity, and colour are all variable as the star pulsates during its eight-day period. The period is slowly increasing. S Sagittae has been reported as a double or triple system with a hotter main sequence