If stars with masses like our Sun's cannot make elements heavier than oxygen, where are heavier elements like silicon produced in the universe? Group of answer choices heavier elements are made in the cores of significantly more massive stars than the Sun, which can get hotter in the middle heavier elements are made in the cores of planets that are molten and hot when they form these heavier elements were made in the Big Bang at the time the universe began, and have been part of the universe ever since this is an unsolved problem in astronomy; no one knows heavier elements are made in the proto-planetary disks that accompany many newly forming stars