How are AGB stars formed?

Jul 15, 2016

Stars between about 0.6 and 10 solar masses use Hydrogen fusion to create energy. When the supply of Hydrogen is exhausted, the star's core starts to collapse under gravity. This causes the temperature to rise and the outer layers expand into a red giant. When the temperature gets to over $3 \cdot {10}^{8}$K Helium fusion starts and the star's luminosity increases.