Answer to Question #153077 in Astronomy | Astrophysics for Muhammad ali

Question

For temperature around 1.5×10^7k in a stellar core,describe why it is hydrogen instead of heaviour ions which undergo fusion.Also,when the temperature is higher, describe why higher mass ions can undergo fusion.

Answer 1

A star’s mass determines its core pressure and temperature and therefore determines its fusion rate. Higher mass stars have hotter cores, faster fusion rates, greater luminosities, and shorter lifetimes.

The high temperature gives the hydrogen atoms enough energy to overcome the electrical repulsion between the protons. Fusion requires temperatures about 100 million Kelvin (approximately six times hotter than the sun's core).