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LBVs and the nature of the S Dor cycles: the case of AG Carinae

J. H. Groh·A. Damineli·D. J. Hillier
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Abstract

We present the results of a detailed spectroscopic analysis of 20 years of observations of AG Carinae using the radiative transfer code CMFGEN. Among the conclusions of this work, we highlight the importance of including time-dependent effects in the analysis of the full S Dor cycle. We obtained that the mass-loss rate is approximately constant during the cool phases, implying that the S Dor-type eruptions begin well earlier than the maximum seen in the visual lightcurve. We also determined that the S Dor cycles are ultimately a consequence of an increase/decrease of the hydrostatic radius in combination with the formation of a pseudo-photosphere.

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J. H. Groh, A. Damineli, D. J. Hillier. 2007-02-22. LBVs and the nature of the S Dor cycles: the case of AG Carinae. https://arxiv.org/abs/astro-ph/0702612

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