If a main-sequence star suddenly started fusing hydrogen at a faster rate in its core, it would become larger, cooler, and more luminous. smaller, cooler, and more luminous. smaller, hotter, and more luminous.

The more compact and more luminous the energy-producing shell becomes, the more the outer parts of the star swell. hs, Core growth and rapid hydrogen fusion feed off each other in a red giant star, causing it to move more and more rapidly up the red giant branch. @ ...a smaller, more massive degen- fi erate He core, which leads to... ae @ ...faster growth of helium B ...stronger gravitational core mass, which leads to... force, which leads to... Red giant la) eel neh Visual luminosity relative to the Sun | y + Surface 8 ...higher pressure in H-fusion temperature (K) shell, which leads to... *S a @ .. faster nuclear fusion, which leads to... 6 .. faster conversion of H to He, which leads to