<P> The most common red giants are stars on the red - giant branch ( RGB ) that are still fusing hydrogen into helium in a shell surrounding an inert helium core . Other red giants are the red - clump stars in the cool half of the horizontal branch , fusing helium into carbon in their cores via the triple - alpha process ; and the asymptotic - giant - branch ( AGB ) stars with a helium burning shell outside a degenerate carbon -- oxygen core , and a hydrogen burning shell just beyond that . </P>
<P> The most common red giants are stars on the red - giant branch ( RGB ) that are still fusing hydrogen into helium in a shell surrounding an inert helium core . Other red giants are the red - clump stars in the cool half of the horizontal branch , fusing helium into carbon in their cores via the triple - alpha process ; and the asymptotic - giant - branch ( AGB ) stars with a helium burning shell outside a degenerate carbon -- oxygen core , and a hydrogen burning shell just beyond that . </P>
a low mass star that converts helium to carbon is a
a low mass star that converts helium to carbon is a
red giants
red giants