Related papers: Ellipsoidal effect in the symbiotic star YY Her
We present photometry and spectroscopy of HT Camelopardalis, a recently discovered X-ray-bright cataclysmic variable. The spectrum shows bright lines of H, He I, and He II, all moving with a period of 0.059712(1) d, which we interpret as…
We analyze $\sim$32 years of optical spectra and photometry for the symbiotic binary PU Vul. Light curves for the He I $\lambda$4471, He II $\lambda$4686 and H$\beta$ $\lambda$4861 emission lines reveal an illumination effect, where the hot…
We analyze the long-term tidal evolution of a single-planet system through the use of numerical simulations and averaged equations giving the variations of semi-major axis and eccentricity of the relative orbit. For different types of…
The obliquities of planet-hosting stars are clues about the formation of planetary systems. Previous observations led to the hypothesis that for close-in giant planets, spin-orbit alignment is enforced by tidal interactions. Here, we…
As a planet orbits, it causes periodic modulations in the light curve of its host star. Due to the combined effects of the planet raising tides on the host star, relativistic beaming of the starlight, and reflection of light off the…
The tidally tilted pulsators are a new type of oscillating star in close binary systems that have their pulsation axis in the orbital plane because of the tidal distortion caused by their companion. We describe this group of stars on the…
Over time, tides synchronize the rotation periods of stars in a binary system to the orbital period. However, if the star exhibits differential rotation then only a portion of it can rotate at the orbital period, so the rotation period at…
We review three main results of our recent study: * We show that a proper treatment of the tidal interaction prior to the onset of the common envelope (CE) leads to an enhance mass loss. This might increase the survivability of planets and…
Most transiting planets orbit very close to their parent star, causing strong tidal forces between the two bodies. Tidal interaction can modify the dynamics of the system through orbital alignment, circularisation, synchronisation, and…
We report the identification of cyclical changes in the orbital period of the eclipsing cataclysmic variable HT Cas. We measured new white dwarf mid-eclipse timings and combined with published measurements to construct an…
The recurrent nova IM Nor is found to have an orbital period of 2.462 h, shown by periodic dips in brightness. This is only the second recurrent nova known to have such a short period. We interpret the light curve as largely produced by a…
This paper presents results from Kepler photometric light curves and high-resolution spectroscopic study of a super Li-rich giant KIC11087027. Using the light curve analysis, we measured the star's rotational period P$_{\rm…
This paper presents estimations on the possibility of detection of ellipsoidal variations by means of measuring brightness of the star distorted by a close massive planet using Wilson-Devinney method. The problem was already discussed by…
A theoretical framework for the determination of tidally induced radial-velocity variations in a component of a close binary is presented. Both the free and the forced oscillations of the component are treated as linear, isentropic…
It is argued that apart from the well known dependence of the Am phenomenon on the mass, age (effective temperature, gravity) and rotation there is also a complex dependence on the orbital parameters in binary systems. This is why the…
VLA, MERLIN and Hubble Space Telescope imaging observations of the extended regions of the symbiotic system CH Cygni are analysed. These extensions are evidence of a strong collimation mechanism, probably an accretion disk surrounding the…
Our aim is to investigate the tidal interaction in High-mass X-ray Binaries and Symbiotic stars in order to determine in which objects the rotation of the mass donors is synchronized or pseudosynchronized with the orbital motion of the…
Stars are stretched by tidal interactions in tight binaries, and changes to their projected areas introduce photometric variations twice per orbit. Hermes et al. (2014, ApJ, 792, 39) utilized measurements of these ellipsoidal variations to…
We searched for circumbinary planets orbiting NY Vir in historical eclipse times including our long-term CCD data. Sixty-eight times of minimum light with accuracies better than 10 s were used for the ephemeris computations. The best fit to…
We present a semi-analytic study of the equilibrium models of close binary systems containing a fluid star (mass $m$ and radius $R_0$) and a Kerr black hole (mass $M$) in circular orbit. We consider the limit $M\gg m$ where spacetime is…