Abundance analyses of a sample of five faint blue stars in the galactic halo

High resolution optical spectra of five faint high galactic latitude B-type stars, identified from a magnitude limited survey, have been analysed using LTE model atmosphere calculations. All targets have small projected rotational velocities (≤30 km s−1) and hence may be evolved objects. This is supported by their chemical compositions, which indicate that they are old Population II stars; two stars also show enhanced nitrogen abundances probably due to the mixing of nuclear processed material to their surfaces. Their atmospheric parameters are consistent with a post-Asymptotic Giant Branch evolutionary status, although two targets may have evolved directly off the horizontal branch.