1996A&A...310..564K

We present equivalent width measurements of lines of HeI, CIII, NIII, OII, MgII and SiIV from high resolution optical spectra of eight blue stragglers towards the young galactic association Perseus OB1, together with similar data from ultraviolet spectra. We have carried out intercomparisons of the observed line strengths between target stars of similar effective temperatures, and comparisons between the target stars and data for other O-type stars, in order to search for possible abundance anomalies in our target stars. We find firm evidence that two stars, HD 12323 and HD 13268, exhibit CNO bicycle processed material at their surfaces, and we outline evolutionary scenarios to explain this phenomenon. One further star, HD 12993, also shows marginal evidence for processed material at its surface. There is no evidence for abundance anomalies in the five remaining stars, and we consider that they may not be association members. Hence their identification as blue stragglers is in doubt.