A high-resolution spectroscopic analysis of the suspected spectroscopic binary HD 165553

Abstract

The results of an analysis of a high-resolution spectrum of the possible spectroscopic binary HD 165553, obtained with a spectral resolving power of ~ 60 000, are presented. A detailed chemical-composition study indicates that the star is a normal super-giant with essentially solar composition expect for the elements C and Na, for which we present; plausible reasons associated with stellar evolution. Comparison of the star’s spectrum with that of γ Cyg, a supergiant of spectral type F8 Iab, indicates that the star is of a later spectral type; we assign a spectral type Go Iab for the star. The star may be a single-lined spectroscopic binary; there is no evidence of double lines in its spectrum. The heliocentric radial velocity of the star is estimated on our spectrum. The heliocentric radial velocity of the star is estimated on our spectrum to be – 4.5 km per second ± 1.5 km per second.