Spectrum is changing

Forums Variable Stars Nova in Cas Spectrum is changing

John Coffin

This is a spectrum from the early hours of 12th August. It looks very different from those of the 30th and 31st July in this thread. The H alpha line is much reduced and there appears to be a P Cygni profile, presumably due to expansion of the nova. I haven’t tried to identify the other broad absorption features. I would be interested in other people’s comments on what this spectrum tells us about the evolution of the nova. I see from the database that others have also noticed the changing profile.