A Dor - An Eclipsing Subdwarf - Brown Dwarf Binary
  AA Dor is an eclipsing, close, post common-envelope binary (PCEB) consisting of a sdOB primary star and an unseen cool companion with an extraordinary low mass.   The evolution of this system appears enigmatic - results of a recent spectral analysis of the primary has shown that the secondary is formally a brown dwarf.   We present results of a spectral analysis which is based on phase-resolved high-resolution and high-SN spectroscopy. 
T. Rauch (Dr.-Remeis-Sternwarte, Bamberg, Germany; Institut fuer   Astronomie und Astrophysik, Tuebingen, Germany)