Type II supernovae show prominent lines of hydrogen in their spectra,whereas hydrogen lines are absent in spectra of Type Ia supernovae.Why is this? (Hint: Think about the type of star that gives rise to each of the two types of supernova. )
A) Massive stars have burned all of their hydrogen into heavier elements,whereas low-mass stars still have large hydrogen-rich envelopes.
B) Massive stars contain large amounts of hydrogen,whereas white dwarfs are mostly carbon and oxygen.
C) White dwarfs have a thick surface layer of hydrogen,whereas neutron stars contain no hydrogen at all.
D) Massive stars contain large amounts of hydrogen,whereas neutron stars contain no hydrogen at all.

Question

Quizplus · Accepted Answer

Type II supernovae result from the collapse of massive stars, which still contain significant amounts of hydrogen in their outer layers. Type Ia supernovae, on the other hand, originate from white dwarfs in binary systems that accumulate matter until they reach a critical mass and explode; these white dwarfs are composed mostly of carbon and oxygen, with no hydrogen layers, hence the absence of hydrogen lines in their spectra.

Type II Supernovae Show Prominent Lines of Hydrogen in Their