What direct evidence do astronomers have that supports the heavy element formation in stars?
A) The presence of technetium in giant star spectra
B) Observed elemental abundances
C) Gamma-ray emissions from decay of cobalt 56 in supernovae
D) Light curves of type-I supernovae
E) All of the above are evidence of this.

Question

Quizplus · Accepted Answer

All of the options listed provide evidence for heavy element formation in stars. 
A) The presence of technetium in giant star spectra is significant because technetium is a radioactive element with a short half-life and should not be present if stars did not create heavy elements.
B) Observed elemental abundances show that heavier elements become more abundant with later generations of star formation, indicating that earlier generations synthesized these heavier elements.
C) Gamma-ray emissions from the decay of cobalt-56 in supernovae directly show the production of heavy elements in the explosion, as cobalt-56 is produced by nuclear fusion in the star prior to the supernova. 
D) Light curves of Type-I supernovae also provide evidence for heavy element formation, as these supernovae are thought to result from the detonation of a white dwarf that has accreted material from a companion star. This material is expected to be enriched in heavy elements, and their light curves and spectra confirm this expectation.

What Direct Evidence Do Astronomers Have That Supports the Heavy