Related papers: Tracing CNO exposed layers in the Algol-type binar…
The eclipsing and double-lined spectroscopic binary V380 Cyg is an extremely important probe of stellar evolution: its primary component is a high-mass star at the brink of leaving the main sequence whereas the secondary star is still in…
A prerequisite for probing theortical evolutionary models for high-mass stars is the determination of stellar physical properties with a high accuracy. We do this for three binary systems containing components with masses above 10 Msun:…
The eclipsing and double-lined spectroscopic binary system V453 Cygni consists of two early B-type stars, one of which is nearing the terminal age main sequence and one which is roughly halfway through its main sequence lifetime. Accurate…
About a quarter of massive binary stars undergo mass transfer while both stars burn hydrogen at their cores, first on the thermal and then on the nuclear timescale. The nuclear timescale mass transfer leads to observable counterparts: the…
Double-lined eclipsing binaries allow accurate and direct determination of fundamental parameters such as mass and radius for each component, and they provide important constraints on the stellar structure and evolution models. In this…
Aims. We present an in-depth study of the two components of the binary system LZCep in order to constrain the effects of binarity on the evolution of massive stars. Methods. We use a set of high-resolution, high signal-to-noise ratio…
The complexity of composite spectra of close binary star system makes study of the spectra of their component stars extremely difficult. For this reason there exists very little information on the photospheric chemical composition of stars…
Multiband CCD photometric observations of SZ Her were obtained between 2008 February and May. The light curve was completely covered and indicated a significant temperature difference between both components. The light-curve synthesis…
Algol-type binary systems are the product of rapid mass transfer between the initially more massive component to its companion. It is still unknown whether the process is conservative, or whether substantial mass is lost from the system.…
The complexity of composite spectra of close binaries makes the study of the individual stellar spectra extremely difficult. For this reason there exists very little information on the chemical composition of high-mass stars in close…
New complete light and radial velocities curves were obtained for the eclipsing binaries CC Her and CM Lac. The data are analysed with modern techniques in order to derive the physical parameters of the systems and study their present…
We present a spectral analysis of the UV-bright star Y453 in M4. Model fits to the star's optical spectrum yield T_eff ~ 56,000 K. Fits to the star's FUV spectrum, obtained with the Cosmic Origins Spectrograph (COS) on board the Hubble…
Interacting binary stars undergo evolution that is significantly different from single stars, thus, a larger sample of such systems with precisely determined stellar parameters is needed to understand the complexities of this process. We…
Binary stars undergoing mass transfer provide unique laboratories for testing stellar evolution. Here, we present a comprehensive photometric and spectroscopic analysis of the semi-detached system ET Cru. Using spectral disentangling, we…
Context: Intermediate-Mass stars are often overlooked as they are not supernova progenitors but still host convective cores and complex atmospheres which require computationally expensive treatment. Due to this, there is a general lack of…
The equivalent widths of C II $\lambda$ 4267 \AA line were measured for the mass-gaining primary stars of the 18 Algol-type binary systems. The comparison of the EWs of the gainers with those of the single standard stars having the same…
This paper presents a detailed analysis of the light and radial velocity curves of the semi-detached eclipsing binary system OGLE-LMC-ECL-09937. The system is composed of a hot, massive and luminous primary star of a late-O spectral type,…
AR Aur A+B is a close binary of astrophysical interest, because dissimilar surface compositions are reported between similar late B-type dwarfs. A new spectroscopic study on this system was carried out based on the disentangled spectra, in…
We present B and R band spectroastrometry of a sample of 45 Herbig Ae/Be stars in order to study their binary properties. All but one of the targets known to be binary systems with a separation of ~0.1-2.0 arcsec are detected by a…
We present the results of a multi-site photometric campaign carried out in 2004-2008 for the Algol-type eclipsing binary system CT Her, the primary component of which shows Delta Scuti-type oscillations. Our data consist of differential…