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Missing Opacity in the Atmospheric Models of Red Giants

C. I. Short·J. B. Lester
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Abstract

Synthetic spectra of Arcturus computed with the latest theoretical stellar atmospheres disagree strongly with both the spectral energy distribution and with the spectroscopic data for $λ< 4000$ Å, even though the stellar parameters are well constrained. We find that the discrepancy can be removed by adding a continuous absorption opacity that is approximately equal to that which is already included in the {\sc atlas9} code. Spectroscopy of other K2 III stars shows that the spectrum of Arcturus in not anomalous. Therefore, missing opacity may be a common feature of the models for stars in this temperature and luminosity range.

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C. I. Short, J. B. Lester. 1994-10-04. Missing Opacity in the Atmospheric Models of Red Giants. https://doi.org/10.1086/187658

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