CARBON ABUNDANCES AND MERIDIONAL MIXING IN RAPIDLY ROTATING EARLY-A STARS

Carbon abundances are obtained from lines of C I at 9100 Å for 22 early-A main-sequence stars with projected rotational velocities of up to 180 km s⁻¹. The abundance shows no significant trend with increasing rotation. A preliminary conclusion is that meridional mixing currents do not bring CN-processed material into the atmospheres of these rotating A stars. Several carbon deficient stars are tentatively identified as chemically peculiar A stars. Future surveys should cover a sufficient wavelength interval to permit a spectral classification and a determination of the microturbulence.