Related papers: An Analytic Model for Blue Straggler Formation in …
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…
It has become clear in recent years that globular clusters are not simple stellar populations, but may host chemically distinct sub-populations, typically with an enhanced helium abundance. These helium-rich populations can make up a…
Globular star clusters that formed at the same cosmic time may have evolved rather differently from a dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend…
We summarize the results of recent theoretical work on the dynamical evolution of globular clusters containing primordial binaries. Even a very small initial binary fraction (e.g., 10%) can play a key role in supporting a cluster against…
Stellar collisions are an important formation channel for blue straggler stars in globular and old open clusters. Hydrodynamical simulations have shown that the remnants of such collisions are out of thermal equilibrium, are not strongly…
We present a technique to identify the most probable dynamical formation scenario for an observed binary or triple system containing one or more merger products or, alternatively, to rule out the possibility of a dynamical origin. Our…
In dense stellar systems, frequent dynamical interactions between binaries lead to the formation of multiple systems. In this contribution we discuss the dynamical formation of hierarchically stable triples: the formation rate, main…
Context. Origin and evolution of blue stragglers in globular clusters is still a matter of debate. Aims. The aim of the present investigation is to reproduce the evolutionary history of four binary blue stragglers in four different…
We present and discuss new BVI CCD photometry in the field of the globular cluster Arp~2, which is considered a member of the Sagittarius Dwarf Spheroidal Galaxy. The main goal of this investigation is to study of the statistics and spatial…
We have surveyed the blue straggler star population of the Galactic globular cluster M5 using high-resolution images of the core along with wide-field ground-based images reaching to more than 19 core radii. To gauge M5's relative…
We analyze the position of the two populations of blue stragglers in the globular cluster M30 in the Hertzsprung-Russell diagram. Both populations of blue stragglers are brighter than the cluster's turn-off, but one population (the blue…
Most of massive stars form in binary or higher-order systems in clumpy, sub-structured clusters. In the very first phases of their life, these stars are expected to interact with the surrounding environment, before being released to the…
We use smoothed-particle hydrodynamics to examine differences between direct collisions of single stars and binary star mergers in their roles as possible blue straggler star formation mechanisms. We find in all cases that core helium in…
Blue straggler stars (BSSs) are the most massive stars in a cluster formed via binary or higher-order stellar interactions. Though the exact nature of such formation scenarios is difficult to pin down, we provide observational constraints…
We investigate the evolution of the radial distribution of Blue Straggler Stars through a set of Monte Carlo simulations of star clusters under a variety of initial conditions. We used a novel technique based on the "artificial…
The paper presents an analysis of properties of populations of blue stragglers (BSs) in evolving globular clusters, based on numerical simulations done with the MOCCA code for various initial globular clusters conditions. We find that…
Blue straggler stars are unique main-sequence stars that appear more luminous, hotter, and therefore younger, than their coeval counterparts. In star clusters, these stars are located above the cluster turn-off in the Hertzsprung-Russell…
Context: The principal mechanism by which brown dwarfs form, and its relation to the formation of higher-mass (i.e. hydrogen-burning) stars, is poorly understood. Aims: We advocate a new model for the formation of brown dwarfs. Methods: In…
Combination of high-precision photometry and spectroscopy allows the detailed study of the upper main sequence in open clusters. We are carrying out a comprehensive study of a number of clusters containing Be stars in order to evaluate the…
Binary systems can evolve into immensely different exotic systems such as blue straggle stars (BSSs), yellow straggler stars, cataclysmic variables, type Ia supernovae depending on their initial mass, the orbital parameters and evolution.…