Indeed an excellent paper by Hugh. Great to see spectra from multiple observers contributing to Hugh’s research on VV Cep.
The shift in central eclipse timing without an apparent long term change in period is a puzzle. It would be interesting to know how accurate the various central timings were over the past hundred years. I wondered whether there was any possibility that different spectral features were used to estimate the central eclipse in early work compared to modern work of the 1990’s and onwards, resulting in a systematic shift in observed in the central time.