Related papers: Alpha Virginis: line-profile variations and orbita…
The orbital decay of binaries containing a primary sub-giant or red giant star and a stellar or substellar companion is investigated. The tide raised in the primary by the companion leads to an exchange of angular momentum between the orbit…
Context: The presence of heavier chemical elements in stellar atmospheres influences the spectral energy distribution (SED) of stars. An uneven surface distribution of these elements, together with flux redistribution and stellar rotation,…
This work is a continuation of the studies of the ultrafast variability of line profiles in the spectra of early-type stars. Line profile variations (LPVs) in the spectrum a chemically peculiar A0Vp star $\alpha^2\,$CVn are investigated…
During the past decade circumbinary disks have been discovered around various young binary stars. Hydrodynamical calculations indicate that the gravitational interaction between the central binary star and the surrounding disk results in…
We report 18 new primary minima timing observations of the short-period eclipsing binary system NY Virginis. We combined these minima with previously published primary minima to update circumbinary exoplanet models in this system based on…
Apsidal motion in massive eccentric binaries offers precious information about the internal structure of the stars. This is especially true for twin binaries consisting of two nearly identical stars. We make use of the tidally induced…
CU Vir and V901 Ori belong among these few magnetic chemically peculiar stars whose rotation periods vary on timescales of decades. We aim to study the stability of the periods in CU Vir and V901 Ori using all accessible observational data…
Context. Establishing the multiplicity of O-type stars is the first step towards accurately determining their stellar parameters. Moreover, the distribution of the orbital parameters provides observational clues to the way that O-type stars…
The angle between the stellar spin-axis and the orbital plane of a stellar or planetary companion has important implications for the formation and evolution of such systems. A study by Hale (1994) found that binaries with separations $a <…
The tidal interaction of a Be star with a binary companion forms two spiral arms that cause orbital modulation of the Be disc structure. The aim of this work is to identify observables in which this modulation is apparent. The structure of…
We reported a cyclic variation of $O-C$ diagram with a semi-amplitude of 0.0033 days and a period of 1.05 years for the pulsating eclipsing binary HZ Dra. The cyclic variation can be explained by the light travel-time effect via the…
Precise radial velocities (RVs) are commonly derived through cross-correlation or template-matching methods, both of which rely on a reference spectrum that can introduce biases when the data are variable, contaminated, or sparsely sampled.…
Serving as the progenitors of electromagnetic and gravitational wave transients, massive stars have received renewed interest in recent years. However, many aspects of their birth and evolution remain opaque, particularly in the context of…
The majority of massive classical Be stars are thought to be binary interactions products. Their rapid rotation and often strong, variable, and emission-line dominated spectrum, make spectroscopic analysis challenging. Hence, robust binary…
Massive stars show a variety of spectral variability: presence of discrete absorption components in UV P-Cygni profiles, optical line profile variability, X-ray variability, radial velocity modulations. Our goal is to study the spectral…
We perform one of the first studies into the nonlinear evolution of tidally excited inertial waves in a uniformly rotating fluid body, exploring a simplified model of the fluid envelope of a planet (or the convective envelope of a…
We present the results of a 3.3-year project to monitor the flux density of Sagittarius A* at 2.0, 1.3, and 0.7 cm with the VLA. The fully calibrated light curves for Sgr A* at all three wavelengths are presented. Typical errors in the flux…
We present preliminary results of our spectroscopic campaign of a group of intermediate mass interacting binaries dubbed "Double Periodic Variables" (DPVs), characterized by orbital light curves and additional long photometric cycles…
Tidal friction has long been recognized to circularize the orbits of binary stars over time. In this study, we use the observed distribution of orbital eccentricities in populations of binary stars to probe tidal dissipation. In contrast to…
We provide a generalized discussion of tidal evolution to arbitrary order in the expansion of the gravitational potential between two spherical bodies of any mass ratio. To accurately reproduce the tidal evolution of a system at separations…