Chemical Composition of 8 OB-Type Stars in the Local Galactic Environment

Abstract We perform a non-local thermodynamic equilibrium spectroscopic analysis of eight OB-type stars in the Solar Neighborhood, using high-resolution spectra obtained with the 0.8-m telescope at Ankara University Kreiken Observatory together with archival ESO/UVES data. Stellar parameters were determined from hydrogen Balmer lines, silicon ionization equilibria, and helium line profiles, while chemical abundances were derived for He, C, N, O, Ne, Mg, Al, Si, S, and Fe. HD 37032 is newly identified as a He-rich peculiar star (He/H ≈+0.33 dex), with asymmetric Hα and O I λ5577 features revealing the presence of circumstellar material. HD 46660, HD 46883, and HD 7694 likewise exhibit mild helium enrichment relative to the solar abundance. HD 29309 is found to be a double-lined spectroscopic binary hosting a Barium-star secondary. An H-R diagram analysis indicates that most of the stars are located close to the main sequence, whereas HD 46883 is classified as a blue supergiant with no strong signatures of CNO mixing. These findings provide new constraints of the chemical diversity and evolutionary pathways of early-type stars in the local Galactic environment.