This substance's spectrum displays the D3 Fraunhofer line. When this substance accretes to the surfa
This substance's spectrum displays the D3 Fraunhofer line. When this substance accretes to the surface of a white dwarf or ceases to be degenerate in contracting stars, its namesake flash occurs. Hans Bethe discovered its production by the CNO cycle, and three units of it combine in a namesake exergonic process that occurs mainly in red giants. This first element to be detected extraterrestrially is the heaviest and last product of the proton-proton chain, the fusion reaction in most stars. For 10 points, identify this second-most abundant element in the universe, named for its abundance in our sun.
This substance's spectrum displays the D3 Fraunhofer line. When this substance accretes to the surface of a white dwarf or ceases to be degenerate in contracting stars, its namesake flash occurs.
helium [nucleus or atom; prompt on "He"; accept alpha particles until "element" is read]