A study of chemical abundances, rotational velocities, and orbital elements in single-lined spectroscopic binary stars in open clusters

Abstract

ABSTRACT Binary interactions play a significant role in stellar evolution. In this study, we present a comprehensive analysis of 17 single-lined spectroscopic binary stars and identify two more as ‘yellow stragglers’, in the context of 15 young open clusters with ages younger than 1.0 Gyr. High-resolution spectroscopy ($R\, \approx \, 48000$) was employed to determine atmospheric parameters and chemical abundances of various elements including Li, C (C2), N (12CN), O, Na, Mg, Al, Ca, Si, Ti, Ni, Cr, Y, Zr, La, Ce, Nd, and Eu, and compared them with the abundances of stars reported in the literature. The projected rotational velocities ($v\, \sin \, \mathrm{ i}$) of 17 stars were determined via the spectral synthesis method. For two stars, we analyse the phenomenon of yellow stragglers based on their spectra and colour–magnitude diagram. Our $v\, \sin \, \mathrm{ i}$ results exhibit excellent agreement with previous studies in the literature for four stars previously analysed. Furthermore, we found a similar set of chemical abundances between thin disc stars and the studied spectroscopic binaries, except for s-process elements, such as La, Ce, and Nd. Also, we confirm that yellow straggler stars are members of binary systems, specifically giant G/K-type stars paired with dwarf A-type stars. Finally, we investigated the relationships between chemical abundances, orbital parameters (obtained from the literature), and $v\, \sin \, \mathrm{ i}$, which can provide insights into the observed anomalies in 7Li abundance in two stars such as NGC 6694-14 and NGC 6709-303. Our findings suggest that the anomalous rotation and lithium enrichment observed in these stars are likely results of interactions within binary companions.