Related papers: Present status of two-dimensional ESTER models: Ap…

We consider the general spatial three body problem and study the dynamics of planetary systems consisting of a star and two planets which evolve into 2/1 mean motion resonance and into inclined orbits. Our study is focused on the periodic…

Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed IR-excess and emission lines. The influence of binarity on these phenomena remains controversial. delta Sco is a…

The study of fundamental properties (such as temperatures, radii, masses, and ages) and interior processes (such as convection and angular momentum transport) of stars has implications on various topics in astrophysics, ranging from the…

Intermediate-mass stars are often fast rotators, and hence are centrifugally flattened and affected by gravity darkening. To analyse this kind of stars properly, one must turn to 2D models to compute the visible radiative flux and to take…

The nature of the first massive stars may be inferred by investigating the origin of the extremely metal-poor (EMP) stars, likely formed from the ejecta of one or a few previous massive stars. We investigate the rotational properties of…

The evolution of massive stars is the basis of several astrophysical investigations, from predicting gravitational-wave event rates to studying star-formation and stellar populations in clusters. However, uncertainties in massive star…

Aim - In this work, a sample of vsini of B9 to F2-type main sequence single stars has been built from highly homogeneous vsini parameters determined for a large sample cleansed from objects presenting the Am and Ap phenomenon as well as…

Eclipsing binary stars have long served as benchmark systems to measure fundamental stellar properties. In the past few decades, asteroseismology - the study of stellar pulsations - has emerged as a new powerful tool to study the structure…

delta Velorum is a nearby (24pc) triple stellar system, containing a close, eclipsing binary (Aa, Ab) discovered in 2000. Multiple systems provide an opportunity to determine the set of fundamental parameters (mass, luminosity, size and…

The evolutionary status of Be-type stars remains unclear, with both single-star and binary pathways having been proposed. Here, VFTS spectroscopy of 73 Be-type stars, in the spectral-type range, B0--B3, is analysed to estimate projected…

This paper develops a novel numerical method for obtaining structures of rapidly rotating stars based on a self-consistent field scheme. The solution is obtained iteratively. Both rapidly rotating barotropic and baroclinic equilibrium…

Stellar rotation has long been recognized as important to the evolution of stars, by virtue of the chemical mixing it can induce and how it interacts with binary mass transfer. Binary interaction and rapid rotation are both common in…

The evolution of triples has not attracted much attention in the literature, although their evolution can be dramatically different from binaries and single stars. Triples are quite common, and we find that for about 1% of the triples in…

The circumstellar medium around massive stars is strongly impacted by stellar winds, radiation, and explosions. We use numerical simulations of these interactions to constrain the current properties and evolutionary history of various stars…

This paper presents a detailed statistical determination of the equatorial rotation rates of classical Be stars. The rapid rotation of Be stars is likely to be linked to the ejection of gas that forms dense circumstellar disks. The physical…

Stellar evolution, a fundamental bedrock of modern astrophysics, is driven by the physical processes in stellar interiors. While we understand these processes in general terms, we lack some important ingredients. Seemingly small…

Massive stars can during their evolution reach the phase of critical (or very rapid, near-critical) rotation when further increase in rotation rate is no longer kinematically allowed. The mass ejection and angular momentum outward transport…

Massive stars are important metal factories in the Universe. They have short and energetic lives, and many of them inevitably explode as a supernova and become a neutron star or black hole. In turn, the formation, evolution and explosive…

From its surface properties it can be difficult to determine whether a red-giant star is in its helium-core-burning phase or only burning hydrogen in a shell around an inert helium core. Stars in either of these stages can have similar…

One of the greatest challenges in interpreting the pulsations of rapidly rotating stars is mode identification, i.e. correctly matching theoretical modes to observed pulsation frequencies. Indeed, the latest observations as well as current…