This Shakespearean sonnet deals with the concept of “We Are Stardust.” Because the heavier elements and molecules that make us up originate inside the hearts of stars by the process of fusion. With the exception of hydrogen, helium and some lithium, all that composes us was forged in the interior of primordial stars. However, fusion alone would be insufficient to provide our raw materials, since these would be bound up inside the stars that made them. To make these constituents available for use, the stars producing them must give up their lives in tremendous explosions that seed the cosmos with these raw materials, hence stardust.
“Pupil,” in the final couplet, is a pun on the part of the eye aimed at the stars and the student who learns from watching our stellar progenitors.