On the sdOB primary of the post common-envelope binary AA Doradus (LB 3459)

Context. AADor is an eclipsing, post common-envelope binary with an sdOB-type primary and a low-mass secondary. Eleven years ago, an NLTE spectral analysis showed a discrepancy in the surface gravity that was derived by radial-velocity and light-curve analysis, log g = 5.21 +/- 0.1 (cm/s(2)) and log g = 5.53 +/- 0.03, respectively. Aims. We aim to determine both the effective temperature and surface gravity of AADor precisely from high-resolution, high-S/N observations taken during the occultation of the secondary. Methods. We calculated an extended grid of metal-line blanketed, state-of-the-art, non-LTE model atmospheres in the parameter range of the primary of AADor. Synthetic spectra calculated from this grid were compared to optical observations. Results. We verify T-eff = 42 000 +/- 1000 K from our former analyses and determine a higher log g = 5.46 +/- 0.05. The main reason are new Stark-broadening tables that were used for calculating of the theoretical Balmer-line profiles. Conclusions. Our result for the surface gravity agrees with the value from light-curve analysis within the error limits, thereby solving the so-called gravity problem in AADor.