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.
@article{arxiv.astro-ph/0311558,
title = {AA Dor - An Eclipsing sdOB - Brown Dwarf Binary},
author = {Thomas Rauch},
journal= {arXiv preprint arXiv:astro-ph/0311558},
year = {2007}
}
Comments
8 pages, 4 figures, Workshop on Extreme Horizontal Branch Stars and Related Objects, Jun 2003, Keele, UK