The eclipsing and double-lined spectroscopic binary system V453 Cygni consists of two early B-type stars , one of which is nearing the terminal age main sequence and one which is roughly halfway through its main sequence lifetime .
Accurate measurements of the masses and radii of the two stars are available , which makes a detailed abundance analysis both more interesting and more precise than for isolated stars .
We have reconstructed the spectra of the individual components of V453 Cyg from the observed composite spectra using the technique of spectral disentangling .
From these disentangled spectra we have obtained improved effective temperature measurements of 27 900 \pm 400 K and 26 200 \pm 500 K , for the primary and secondary stars respectively , by fitting non-LTE theoretical line profiles to the hydrogen Balmer lines .
Armed with these high-precision effective temperatures and the accurately known surface gravities of the stars we have obtained the abundances of helium and metallic elements .
A detailed abundance analysis of the primary star shows a normal ( solar ) helium abundance if the microturbulence velocity derived from metallic lines is used .
The elemental abundances show no indication that CNO-processed material is present in the photosphere of this high-mass terminal age main sequence star .
The elemental abundances of the secondary star were derived by differential study against a template spectrum of a star with similar characteristics .
Both the primary and secondary components display elemental abundances which are in the ranges observed in the Galactic OB stars .