The Future of Our Sun: From Main Sequence to Red Giant скачать в хорошем качестве

The Future of Our Sun: From Main Sequence to Red Giant

This is a short snip of an upcoming lecture. In this lecture, you’ll learn about the future evolution of sun-like stars, focusing on the sun’s journey over the next several billion years. When the sun reaches about 10.9 billion years old, its core will run out of hydrogen, forming an inert helium core. This core will contract and heat up but won’t ignite helium fusion. Instead, hydrogen burning will shift to a shell around the core, causing the star’s surface temperature to drop, its radius to expand, and its luminosity to increase. This transition will mark the sun’s movement into the subgiant phase, where it will remain for about 1.5 billion years, growing larger and losing mass through stellar wind. Eventually, the inert core will reach a critical mass, leading to further collapse. This will signal the sun’s shift towards becoming a red giant, characterized by significant expansion, a decrease in surface temperature, and increased opacity due to hydrogen minus ions in the outer layers. These changes will result in the creation of a deep convection zone, efficient energy transfer, and further collapse of the helium core, which will rely on electron degeneracy pressure to prevent a complete collapse. The lecture will detail how these changes align with stellar models and the broader implications for star evolution. #StellarEvolution #SunLifeCycle #Astronomy #Astrophysics #RedGiant #StarFormation #HeliumCore #SubgiantPhase #SpaceScience #FutureOfTheSun