摘要：Context.Extreme super-solar abundances of lithium and beryllium have been reported in recent years for classical novae based on absorption lines in ultraviolet and optical spectra during the optically thick stages, but these findings have not been compared with spectrum syntheses of the ejecta.Aims.We present a grid of nova ejecta models calculated withPHOENIXaimed at simulating the reported Li Iand Be IIfeatures with super-solar abundances.Methods.We computed a sequence of models, finely exploring the parameter space of effective temperature, ejecta expansion velocity, and Li and Be overabundances.Results.Regardless of temperature and expansion velocity, the synthetic spectra for large Li and Be overabundances strongly disagree with those presented in recent literature. Assuming a wide range of Be overabundances (factors of 100 to 10 000 relative to solar), we predict a much stronger spectroscopic feature at Be II3130 Å than those so far observed. A similar overabundance for Li would instead result in a barely observable change in the emitted flux at Li I6709 Å. The observed extended absorption feature at 3131 Å reported inV838 Herand other novae appears even in zero-Be models with only solar abundances (which for novae are underestimates).Conclusions.The computed spectra do not support the lithium and beryllium abundances, and caution is warranted in the interpretation of the phenomenology.
