THE CARBON ABUNDANCE IN MAIN-SEQUENCE B-TYPE STARS TOWARDS THE GALACTIC ANTI-CENTER

Differential carbon abundances (based on the C II doublet at 6580 Angs trom) are presented for eight early type stars, towards the Galactic a nti-centre. All the stars have similar atmospheric parameters with eff ective temperatures in the range 25000-29000 K and surface gravities b etween log g = 3.9-4.3 dex. The derived photospheric abundances vary b y up to 0.6 dex, and with the exception of one star, RLWT-41, the diff erential abundances are found to be closely correlated with those of n itrogen. This implies that both elements may have been formed by simil ar mechanisms and that the lack of correlation between the nitrogen an d oxygen abundances previously found in this sample is not directly du e to CNO-processed core material being mixed to the stellar surface.