Fast rotating Blue Stragglers prefer loose clusters

Abstract

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 analyze 320 high-resolution spectra of blue stragglers collected in eight galactic globular clusters with different structural characteristics and show evidence that the fraction of fast rotating blue stragglers (with rotational velocities larger than 40 km/s) increases for decreasing central density of the host system. This trend suggests that fast spinning blue stragglers prefer low-density environments and promises to open an unexplored route towards understanding the evolutionary processes of these stars. Since large rotation rates are expected in the early stages of both formation channels, our results provide direct evidence for recent blue straggler formation activity in low-density environments and put strong constraints on the timescale of the collisional blue straggler slow-down processes.

Published in Nature Communications

References in corpus (11)

• Improved angular momentum evolution model for solar-like stars II. Exploring the mass dependence
• Dynamical age differences among coeval star clusters as revealed by blue stragglers
• Calibrating Gyrochronology using Kepler Asteroseismic targets
• The updated BaSTI stellar evolution models and isochrones: II. alpha-enhanced calculations
• Discovery of Carbon/Oxygen depleted Blue Straggler Stars in 47 Tucanae: the chemical signature of a mass-transfer formation process
• Investigating mass segregation process in globular clusters with Blue Straggler Stars: the impact of dark remnants
• A Correlation between Blue Straggler and Binary Fractions in the core of Galactic Globular Clusters
• Discovery of a double Blue Straggler sequence in M15: new insight into the core-collapse process
• Spectral Energy Distribution of Blue Stragglers in the core of 47 Tucanae
• Spinning like a Blue Straggler: the population of fast rotating Blue Straggler stars in Omega Centauri
• Contribution of primordial binary evolution to the two blue-straggler sequences in globular cluster M30