Related papers: Blue Stragglers as Stellar Collision Products: the…
A significant fraction of stars experience close interactions, including collisions resulting from gravitational encounters and mergers within close binary systems. These processes can produce more massive stars that may give rise to…
We systematically study the effects of collisions on the overall dynamical evolution of dense star clusters using Monte Carlo simulations over many relaxation times. We derive many observable properties of these clusters, including their…
Many close stellar binaries are accompanied by a far-away star. The "eccentric Kozai-Lidov" (EKL) mechanism can cause dramatic inclination and eccentricity fluctuations, resulting in tidal tightening of inner binaries of triple stars. We…
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…
Recent models of rotating massive stars including magnetic fields prove it difficult for the cores of single stars to retain enough angular momentum to produce a collapsar and gamma-ray burst. At low metallicity, even very massive stars may…
The angular momentum of galaxies controls the kinematics of their stars, which in turn drives observable quantities such as the apparent radius, the bulge fraction, and the alignment with other nearby structures. To show how angular…
The angular momentum (AM) evolution of stellar interiors, along with the resulting rotation rates of stellar remnants, remains poorly understood. Asteroseismic measurements of red giant stars reveal that their cores rotate much faster than…
Star-disk interaction is thought to drive the angular momentum evolution of young stars. In this review, I present the latest results obtained on the rotational properties of low mass and very low mass pre-main sequence stars. I discuss the…
Rotation plays a key role in the star-formation process, from pre-stellar cores to pre-main-sequence (PMS) objects. Understanding the formation of massive stars requires taking into account the accretion of angular momentum during their PMS…
This study focuses on stars with masses above the Kraft break in the \textit{Kepler} field. Their rotational angular momenta are essentially the same as those at the zero-age main sequence. The angular momentum dissipation experienced by…
(Edited) Many fast rotator stars (rotation periods of < 2 days) are found in unresolved binaries with separations of tens of au. This correlation leads to the question of whether the formation of binary stars inherently produces fast…
We examine the blue straggler populations of 13 low-luminosity (M_V_t >~ -6) globular clusters and 2 old open clusters. These clusters test blue straggler formation in environments intermediate between higher luminosity (and usually higher…
We study the angular momentum evolution of binaries containing two white dwarfs which merge and become cool helium-rich supergiants. Our object is to compare predicted rotation velocities with observations of highly evolved stars believed…
Magnetic stresses collimate protostellar winds into a common distribution of force with angle. Sweeping into the ambient medium, such winds drive bipolar molecular outflows whose properties are insensitive to the distribution of ambient gas…
We discuss some aspects of stellar evolution in binary systems. While single stars can swell following the chemical evolution of their interior, stars belonging to binary systems cannot overflow the size of the Roche lobe and hydrostatic…
Binary population synthesis shows that mass transfer from a giant star to a main-sequence (MS) companion may account for some observed long-orbital period blue stragglers. However, little attention {\bf is paid to this blue straggler…
In this paper, we present the simulations for the primordial blue stragglers in the old open cluster M67 based on detailed modelling of the evolutionary processes. The principal aim is to discuss the contribution of mass transfer between…
Blue straggler stars are more massive than the average star in globular clusters, as they originate from the merger of two stars. Consequently, they experience dynamical friction, progressively sinking to the cluster center. Recently,…
Sub-subgiants are a new class of stars that are optically redder than normal main-sequence stars and fainter than normal subgiant stars. Sub-subgiants, and the possibly related red stragglers (which fall to the red of the giant branch),…
From this vast subject, I will pick out and review three specific topics, namely the formation and evolution of bars, the formation of bulges, and the evolution during multiple major mergers. Bars form naturally in galactic discs. Their…