iron. Spectra like the one seen here permit astronomers to make inferences about conditionsΓÇö temperature, density, etc.ΓÇöinside the nebula. One can infer, for example, that the elements the bumps represent are present in the nebula and that they are very hot (tens of millions of degrees Kelvin), which explains why they register in x-ray. Also, because the bumps are characteristic of heavy elements, which can be created only deep within stars, one can assume that the material emitting this radiation was originally inside the progenitor star. Finally, since heavy elements are necessary to build planetary systems and sustain life, one can infer that supernovae play a role in the creation of rich and fertile planets like Earth.
