How do Type Ib and Type Ic supernovae differ regarding their spectral lines?

Answer

Type Ib has helium lines, Type Ic lacks both hydrogen and helium lines.

Both are core-collapse events, but Type Ib spectra show helium lines despite lacking hydrogen, whereas Type Ic lacks both hydrogen and helium lines, indicating more extensive prior mass loss.

How do Type Ib and Type Ic supernovae differ regarding their spectral lines?
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