Related papers: Blue Stragglers as Tracers of Globular Cluster Evo…
Blue stragglers in globular clusters are abnormally massive stars that should have evolved off the stellar main sequence long ago. There are two known processes that can create these objects: direct stellar collisions and binary evolution.…
Blue stragglers are thought to be formed from the merger or coalescence of two stars, but the details of their formation in clusters has been difficult to disentangle. We discuss the two main formation mechanisms for blue stragglers…
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…
Stars in globular clusters are generally believed to have all formed at the same time, early in the Galaxy's history. 'Blue stragglers' are stars massive enough that they should have evolved into white dwarfs long ago. Two possible…
Blue stragglers are anomalously massive core hydrogen-burning stars that, according to the theory of single star evolution, should not exist. They are suspected to form in mass-enhancement processes, involving binary evolution or stellar…
Globular clusters are among the most congested stellar systems in the Universe. Internal dynamical evolution drives them toward states of high central density, while simultaneously concentrating the most massive stars and binary systems in…
Blue stragglers have been found in all populations. These objects are important in both stellar evolution and stellar population synthesis. Much evidence shows that blue stragglers are relevant to primordial binaries. Here, we summarize the…
Two blue-straggler sequences discovered in globular cluster M30 provide a strong constraint on the formation mechanisms of blue stragglers. We study the formation of the blue-straggler binaries through binary evolution, and find that binary…
Blue stragglers are anomalously luminous core hydrogen-burning stars formed through mass-transfer in binary/triple systems and stellar collisions. Their physical and evolutionary properties are largely unknown and unconstrained. Here we…
The formation of blue stragglers is still not completely understood, particularly the relationship between formation environment and mechanism. We use a large, homogeneous sample of blue stragglers in the cores of 57 globular clusters to…
We present an analytic model for blue straggler formation in globular clusters. We assume that blue stragglers are formed only through stellar collisions and binary star evolution, and compare our predictions to observed blue straggler…
Blue straggler stars (BSSs) are stars observed to be hotter and bluer than other stars with the same luminosity in their environment. As such they appear to be much younger than the rest of the stellar population. Two main channels have…
Recent high-resolution observations of the central region of Galactic globular clusters have shown the presence of a large variety of exotic stellar objects whose formation and evolution may be strongly affected by dynamical interactions.…
We investigate the structure and evolution of blue stragglers stars which were formed from direct stellar collisions between main sequence stars in globular clusters. In particular, we look at the rotational evolution of the products of…
We present preliminary results obtained from the comparison of the specific frequencies of Blue Straggler Stars (BSS) detected so far in a sample of 26 Galactic globular clusters. The number of BSS seems to increase almost linearly with…
Recent HST observations of a large sample of globular clusters reveal that every cluster contains between 40 and 400 blue stragglers. The population does not correlate with either stellar collision rate (as would be expected if all blue…
This chapter describes the current state of models of individual blue stragglers. Stellar collisions, binary mergers (or coalescence), and partial or ongoing mass transfer have all been studied in some detail. The products of stellar…
In this paper I present an overview of the main observational properties of a special class of exotic objects (the so-called Blue Straggler Stars, BSSs) in Galactic Globular Clusters (GCs). The BSS specific frequency and their radial…
This chapter explores how we might use the observed {\em statistics} of blue stragglers in globular clusters to shed light on their formation. This means we will touch on topics also discussed elsewhere in this book, such as the discovery…
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…