Related papers: The Blue Stragglers of the Old Open Cluster NGC 18…
(abridged) We present an in-depth study of the hard-binary population of the old (7 Gyr) open cluster NGC 188. The main-sequence solar-type hard binaries in NGC 188 are nearly indistinguishable from similar binaries in the Galactic field.…
(Abridged) Following on from a recently completed radial-velocity survey of the old (7 Gyr) open cluster NGC 188 in which we study in detail the solar-type hard binaries and blue stragglers of the cluster, here we investigate the dynamical…
In open star clusters, where all members formed at about the same time, blue straggler stars are typically observed to be brighter and bluer than hydrogen-burning main-sequence stars, and therefore should already have evolved into giant…
We present 98 spectroscopic binary orbits resulting from our ongoing radial-velocity survey of the old (7 Gyr) open cluster NGC 188. All but 13 are high-probability cluster members based on both radial-velocity and proper-motion membership…
We propose a formation mechanism for twin blue stragglers (BSs) in compact binaries that involves mass transfer from an evolved outer tertiary companion on to the inner binary via a circumbinary disk. We apply this scenario to the observed…
We present a direct N-body simulation modeling the evolution of the old (7 Gyr) open cluster NGC 188. This is the first N-body open cluster simulation whose initial binary population is directly defined by observations of a specific open…
We present 35 new spectroscopic-binary orbits from our extended radial-velocity (RV) survey of the old ($6.4 \pm 0.2$ Gyr) open cluster NGC 188. Using data from the WIYN Open Cluster Study (WOCS) and APOGEE-2, this work nearly doubles the…
Several possible formation pathways for blue straggler stars have been developed recently, but no one pathway has yet been observationally confirmed for a specific blue straggler. Here we report the first findings from a Hubble Space…
At an age of 4 Gyr, typical solar-type stars in M67 have rotation rates of 20-30 days. Using K2 Campaign 5 and 16 light curves and the spectral archive of the WIYN Open Cluster Study, we identify eleven three-dimensional kinematic members…
We have analyzed high-resolution spectra of relatively cool blue stragglers and main sequence turnoff stars in the old open cluster M67 (NGC 2682). We attempt to identify blue stragglers whose spectra are least contaminated by 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…
We introduce the stellar sample of the WIYN Open Cluster Study radial-velocity survey for the rich open cluster NGC 7789 (1.6 Gyr, [Fe/H] = +0.02). This sample lies within an 18$'$ circular radius from the cluster center (10 pc in…
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…
Spectroscopic observations of binary stars in globular clusters are essential to shed light on the poorly constrained period, eccentricity, and mass ratio distributions and to develop an understanding of the formation of peculiar stellar…
We present results of a Hubble Space Telescope far-ultraviolet (FUV) survey searching for white dwarf (WD) companions to blue straggler stars (BSSs) in open cluster NGC 188. The majority of NGC 188 BSSs (15 of 21) are single-lined binaries…
WOCS 4540 is the longest orbital period ($P_{\rm orb}=3030$ days) blue straggler (BSS) - white dwarf (WD) pair in the old open cluster NGC 188 . It also contains one of the most luminous BSS in the cluster. Prior \textit{Hubble Space…
We present a detailed investigation of the radial distribution of blue straggler star and binary populations in the Galactic globular cluster NGC 5466, over the entire extension of the system. We used a combination of data acquired with the…
The old open cluster M67 is an ideal testbed for current cluster evolution models because of its dynamically evolved structure and rich stellar populations that show clear signs of interaction between stellar, binary and cluster evolution.…
Evolutionary pathways of binary systems are vastly different from single stellar evolution, and thus, there is a need to quantify their frequency and diversity. Open clusters are the best test-bed to unveil the secrets of binary populations…
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…