Red giant and helium core flash. When the ascent of the red-giant branch ends they puff off their outer layers much like a post-asymptotic-giant-branch star and then become a white dwarf. Very low mass stars are fully convective and may continue to fuse hydrogen into helium for up to a trillion years until only a small fraction of the entire star is hydrogen. Luminosity and temperature steadily increase during this time, just as for more-massive main-sequence stars, but the length of time involved means that the temperature eventually increases by about 50% and the luminosity by around 10 times. Eventually the level
Triatomic hydrogen gas was unstable, but at the same time also confirmed that the cation existed. In 1917 Gerald Wendt and William Duane discovered that hydrogen gas subjected to alpha particles shrank in volume and thought that diatomic hydrogen was converted to triatomic. After this researchers thought that active hydrogen could be the triatomic form. Joseph Lévine went so far as to postulate that low pressure systems on the Earth happened due to triatomic hydrogen high in the atmosphere. In 1920 Wendt and Landauer named the substance "Hyzone" in analogy to ozone and its extra reactivity over normal hydrogen. Earlier Gottfried Wilhelm