After it experiences a "helium flash" a star like the. Sun will have a brief period of stability, fusing helium into carbon (and sometimes oxygen). During this brief stable stage, the star returns to the position on the H-R diagram that the star had in its main-sequence stage is able to fuse many of the heaviest elements (such as iron and gold) in its superhot core shrinks and heats up, causing the star to decrease its overall luminosity expands and cools, causing the star to increases tremendously in luminosity gets to be even larger in diameter than it was as a red giant Question 4 Choose the star below that is most likely to end its life as a core-collapse supernova. An M3 III star A G2V star A star like the Sun An 05V star An MoV star.