Disentangling component spectra of , a spectroscopic binary with a pulsating primary
^*

I. Improved physical elements and analysis of periodic rapid variations of scalar quantities

¹ Astronomical Institute of the Charles University, V Holešovičkách 2, 18000 Praha 8, Czech Republic e-mail: hec@sunstel.asu.cas.cz
² Astronomical Institute, Academy of Sciences, 25165 Ondřejov, Czech Republic
³ Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 B, 3001 Leuven, Belgium

Received: 12 February 2004
Accepted: 11 April 2004

Abstract

A new reduction and a new analysis of a rich series of high-S/N spectra of the bright star is carried out to test the technique of spectral disentangling in the case when one of the components is a non-radial oscillator. We improve the orbital elements of the system and find the basic physical properties of the binary to be T_eff  = 24 500 K, masses of 10.7–11.9  and 9.6–10.7  and the primary radius and rotational period of 7–8   and 356–368, respectively. This also implies log g  = 3.70–3.78 [cgs]. KOREL disentangling is applied and we find that it worked properly and was not misled by the complex line-profile variability of the pulsating primary. Moreover, the pulsational frequencies are detected via the period search in the line intensities and radial-velocity residuals of the primary derived by KOREL and in the time series of residual spectra in the rest frame of the primary after KOREL disentangling. This constitutes a much better starting point to interpret the complex pixel-by-pixel variations of the disentangled profiles of the primary in terms of stellar oscillations and/or additional rotational modulation than the original spectra before disentangling.