Question

In what type of star would helium be converted to carbon as the final stage of fusion?

Answer 1

The correct answer is red giants.  

Red giants refer to the stars, which have lost the supply of hydrogen in the cores and have started thermonuclear fusion of hydrogen in a shell enveloping the core. They have dimensions ten to hundreds of times bigger than that of the Sun. However, their outer covering is less in temperature, providing them a reddish-orange hue.  

The Sun and any kind of red dwarfs above about 0.25 solar masses, will arise into what is known as a red giant, a later phase of stellar evolution. At this phase, the star begins to combine with various elements, and finally throws off its layers as a planetary nebula, leaving behind a white dwarf of oxygen and carbon.  

Answer 2

Brown Dwarf is the answer