scholarly journals Blue Stragglers in Old Open Clusters: Implications of Their Spectra.

1966 ◽  
Vol 71 ◽  
pp. 383 ◽  
Author(s):  
Armin J. Deutsch
2006 ◽  
Vol 455 (1) ◽  
pp. 247-254 ◽  
Author(s):  
B. Tian ◽  
L. Deng ◽  
Z. Han ◽  
X. B. Zhang

1996 ◽  
Vol 160 ◽  
pp. 541-542 ◽  
Author(s):  
Sverre Aarseth ◽  
Rosemary Mardling

We useN-body simulations of open clusters to examine the evolutionary history of binaries containing neutron stars. The model includes consistent treatment of all the relevant processes (Aarseth 1996):•Synthetic stellar evolution–mass and radius as a function of time (Eggleton et al. 1989)•Accurate treatment of close encounters–Perturbations of binaries and stable multiple systems - Exchange reactions (involving triple and binary-binary interactions) - Collisions → blue stragglers•Binary evolution (primordial and dynamically formed)–Tidal interactions (Mardling & Aarseth 1996) - Stable mass transfer - Common envelope evolution - Magnetic braking - Gravitational radiation - Mergers (including blue stragglers)•Mass loss–Stellar winds - Supernovae - Evaporation of stars from the cluster•Neutron star formation–Supernovae with kick velocities of Lyne & Lorimer (1994), Drukier (1996) - Accretion-induced collapse


Author(s):  
Vikrant V Jadhav ◽  
Clara M Pennock ◽  
Annapurni Subramaniam ◽  
Ram Sagar ◽  
Prasanta Kumar Nayak

Abstract We present a study of six open clusters (Berkeley 67, King 2, NGC 2420, NGC 2477, NGC 2682 and NGC 6940) using the Ultra Violet Imaging Telescope (UVIT) aboard ASTROSAT and Gaia EDR3. We used combinations of astrometric, photometric and systematic parameters to train and supervise a machine learning algorithm along with a Gaussian mixture model for the determination of cluster membership. This technique is robust, reproducible and versatile in various cluster environments. In this study, the Gaia EDR3 membership catalogues are provided along with classification of the stars as members, candidates and field in the six clusters. We could detect 200–2500 additional members using our method with respect to previous studies, which helped estimate mean space velocities, distances, number of members and core radii. UVIT photometric catalogues, which include blue stragglers, main-sequence and red giants are also provided. From UV–Optical colour-magnitude diagrams, we found that majority of the sources in NGC 2682 and a few in NGC 2420, NGC 2477 and NGC 6940 showed excess UV flux. NGC 2682 images have ten white dwarf detection in far-UV. The far-UV and near-UV images of the massive cluster NGC 2477 have 92 and 576 members respectively, which will be useful to study the UV properties of stars in the extended turn-off and in various evolutionary stages from main-sequence to red clump. Future studies will carry out panchromatic and spectroscopic analysis of noteworthy members detected in this study.


1976 ◽  
Vol 32 ◽  
pp. 357-364
Author(s):  
E.S. Pendl ◽  
W. Seggewiss

SummaryA list of open clusters with blue stragglers studied for Ap characteristics is presented. In addition to previously published results new spectroscopic data are given of blue stragglers in the open cluster IC 4756 derived from ESO spectrograms taken in 1973. Preliminary conclusions concerning the status of Ap stars and blue stragglers are drawn.


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