Related papers: Be discs in binary systems I. Coplanar orbits
Rapid rotation is a fundamental characteristic of classical Be stars and a crucial property allowing for the formation of their circumstellar disks. Past evolution in a mass and angular momentum transferring binary system offers a plausible…
We study the evolution of circumbinary disks under the gravitational influence of the binary using two-dimensional hydrodynamical simulations to investigate the impact of disk and binary parameters on the dynamical aspects of the disk. To…
In our current interpretation of the hierarchical structure of the universe it is well established that galaxies collide and merge with each other during their lifetime. If massive black holes (MBHs) reside in galactic centres, we expect…
Among the extrasolar planetary systems about 30 are located in a stellar binary orbiting one of the stars, preferably the more massive primary. The dynamical influence of the second companion alters firstly the orbital elements of the…
We present the results of non linear, hydrodynamic simulations, in three dimensions, of the tidal perturbation of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc mid-plane. The…
To date, several exoplanets have been discovered orbiting stars with close binary companions (a~<30 AU). The fact that planets can form in these dynamically challenging environments implies that planet formation must be a robust process.…
Accretion discs are common in binary systems, and they are often found to be misaligned with respect to the binary orbit. The gravitational torque from a companion induces nodal precession in misaligned disc orbits. We calculate whether…
As of today over 40 planetary systems have been discovered in binary star systems. In all cases the configuration appears to be circumstellar, where the planets orbit around one of the stars, the secondary acting as a perturber. The…
Binary stars are as common as single stars. The number of detected planets orbiting binaries is rapidly increasing thanks to the synergy between transit surveys, Gaia and high-resolution direct imaging campaigns. However, global planet…
This paper will review the status of our observations and understanding of Be stars in X-ray binary systems. In virtually all cases the binary partner to the Be star is a neutron star. The circumstellar disk provides the accretion fuel and…
The discovery of planets in close orbits around binary stars raises questions about their formation. It is believed that these planets formed in the outer regions of the disc and then migrated through planet-disc interaction to their…
The most puzzling property of the extrasolar planets discovered by recent radial velocity surveys is their high orbital eccentricities, which are very difficult to explain within our current theoretical paradigm for planet formation.…
Be stars are main-sequence massive stars with emission features in their spectrum, which originates in circumstellar gaseous discs. Even though the viscous decretion disc (VDD) model can satisfactorily explain most observations, two…
In a population of multiple protostellar systems with discs, the sub-population of circumbinary discs whose orbital plane is highly misaligned with respect to the binary's orbital plane constrains the initial distribution of orbital…
We consider the dynamics of a protostellar disc in a binary system where the disc is misaligned with the orbital plane of the binary, with the aim of determining the observational consequences for such systems. The disc wobbles with a…
We present a comparative study of the circumstellar disks in Be/X-ray binaries and isolated Be stars based upon the H-alpha emission line. From this comparison it follows that the overall structure of the disks in the Be/X-ray binaries is…
Many recent observational studies have concluded that planetary systems commonly exist in multiple-star systems. At least ~20% of the known extrasolar planetary systems are associated with one or more stellar companions. The orbits of…
Triple stellar systems allow us to study stellar processes that cannot be attained in binary stars. The evolutionary phases in which the stellar members undergo mass exchanges can alter the hierarchical layout of these systems. Yet, the…
We study the interactions between a protostar and its circumstellar disc under the influence of an external binary companion to determine the evolution of the mutual stellar spin - disc misalignment angle. The gravitational torque on the…
Context. The presence of a stellar companion can strongly influence the architecture and long-term stability of planetary systems. Motivated by the discovery of exoplanets exhibiting extremely high eccentricities (e >= 0.8) in systems with…