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AA Dor - An Eclipsing sdOB - Brown Dwarf Binary

Thomas Rauch
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Abstract

AA Dor is an eclipsing, close, post common-envelope binary consisting of a sdOB primary star and an unseen secondary with an extraordinary small mass - formally a brown dwarf. The brown dwarf may have been a former planet which survived a common envelope phase and has even gained mass. A recent determination of the components' masses from results of NLTE spectral analysis and subsequent comparison to evolutionary tracks shows a discrepancy to masses derived from radial-velocity and the eclipse curves. Phase-resolved high-resolution and high-SN spectroscopy was carried out in order to investigate on this problem. We present results of a NLTE spectral analysis of the primary, an analysis of its orbital parameters, and discuss possible evolutionary scenarios.

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Thomas Rauch. 2003-11-25. AA Dor - An Eclipsing sdOB - Brown Dwarf Binary. https://arxiv.org/abs/astro-ph/0311558

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