“In the Atacama, I saw the future, when the sun eats up the last of its hydrogen and burns into its red-giant phase, big enough to cook life and clouds and oceans off this naked orb. It wouldn't be a fast process, not by our standards. Millions of years in the execution, our sky would finally be half filled by a sun the color of a red-hot moonrise. After that, the sun would probably collapse into a white dwarf, meanwhile blasting away its outer shells of gas into an explosive planetary nebula. I imagine that all of our minerals will pay off as we make a rainbow streak flaring off into space. We will be beautiful.” EarthSunDesertMineralsChileImagining The FutureAtacamaWhite DwarfDying StarsRed Giant Book:Apocalyptic Planet: Field Guide to the Ever-Ending Earth Source: Apocalyptic Planet: Field Guide to the Ever-Ending Earth
“While a star is on the main sequence, it makes only helium. A star leaves the main sequence when it exhausts the supply of available hydrogen in its core. The post-main sequence fate of the star, and the range of elements produced, depends on the mass of the star. The lowest mass M stars, roughly below .2 Solar masses, are well mixed and can always bring hydrogen from outer layers to the core to sustain fusion. Such stars become gradually more luminous over trillions of years as they convert their hydrogen into helium, until they exhaust their fuel and fade away as white dwarf stars. White dwarf stars are no longer producing energy by fusion. Because of contraction, their surface temperatures are high (hence their bluish-white colour), but they have low luminosity because they are very small. White dwarfs are a common form of stellar remnant. All white dwarfs eventually cool down and go dark, but this process takes many times the current age of the Universe.” Stellar EvolutionWhite DwarfMain Sequence Book:Planetary Systems: A Very Short Introduction Source: Planetary Systems: A Very Short Introduction