Why Is the Spectral Sequence of Stars Not Alphabetical

question 71

Multiple Choice

Why is the spectral sequence of stars not alphabetical?

• A)The letters refer to the initials of the original discovers.
• B)The original alphabetical labeling did not correspond to surface temperature and thus had to be reordered.
• C)They were chosen to fit a mnemonic.
• D)Because there is still uncertainty over what generates the energy in stellar cores.
• E)Because it refers to stellar masses and these were difficult to measure accurately.