Question

When either low-mass or high-mass main sequence stars run out of hydrogen in the core, the core will contain .

Answer 1

It may be the yellow main sequence stars: in the core of a low mass star, four hydrogen nuclei fuse into a single helium nucleus by the series of reactions know as the proton-proton chain.

Answer 2

When main sequence stars run out of hydrogen in the core, then the core will contain Helium on e2020.

The main sequence starts combine with hydrogen atoms to form helium atoms in their cores. About 90% of stars in the universe, including sun are considered as main sequence stars.

These stars can range from about one-tenth of mass of the sun to about 200 times as massive.